Guide to the Secure Configuration of Fedora

with profile CUSP - Common User Security Profile for Fedora Workstation
This profile contains rules to harden Fedora Linux according to the Common User Security Guide for Fedora Workstation.
This guide presents a catalog of security-relevant configuration settings for Fedora. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the scap-security-guide package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.

Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.
Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.

Profile Information

Profile TitleCUSP - Common User Security Profile for Fedora Workstation
Profile IDxccdf_org.ssgproject.content_profile_cusp_fedora

CPE Platforms

  • cpe:/o:fedoraproject:fedora:36
  • cpe:/o:fedoraproject:fedora:37
  • cpe:/o:fedoraproject:fedora:38
  • cpe:/o:fedoraproject:fedora:39
  • cpe:/o:fedoraproject:fedora:40

Revision History

Current version: 0.1.68

  • draft (as of 2023-06-15)

Table of Contents

  1. System Settings
    1. Installing and Maintaining Software
    2. Account and Access Control
    3. System Accounting with auditd
    4. GRUB2 bootloader configuration
    5. Configure Syslog
    6. Network Configuration and Firewalls
    7. File Permissions and Masks
    8. SELinux
  2. Services
    1. Cron and At Daemons
    2. DHCP
    3. DNS Server
    4. FTP Server
    5. Web Server
    6. IMAP and POP3 Server
    7. Mail Server Software
    8. NFS and RPC
    9. Network Time Protocol
    10. Obsolete Services
    11. Proxy Server
    12. Samba(SMB) Microsoft Windows File Sharing Server
    13. SNMP Server
    14. SSH Server

Checklist

Group   Guide to the Secure Configuration of Fedora   Group contains 93 groups and 272 rules
Group   System Settings   Group contains 55 groups and 191 rules
[ref]   Contains rules that check correct system settings.
Group   Installing and Maintaining Software   Group contains 6 groups and 16 rules
[ref]   The following sections contain information on security-relevant choices during the initial operating system installation process and the setup of software updates.
Group   System and Software Integrity   Group contains 1 group and 7 rules
[ref]   System and software integrity can be gained by installing antivirus, increasing system encryption strength with FIPS, verifying installed software, enabling SELinux, installing an Intrusion Prevention System, etc. However, installing or enabling integrity checking tools cannot prevent intrusions, but they can detect that an intrusion may have occurred. Requirements for integrity checking may be highly dependent on the environment in which the system will be used. Snapshot-based approaches such as AIDE may induce considerable overhead in the presence of frequent software updates.
Group   System Cryptographic Policies   Group contains 7 rules
[ref]   Linux has the capability to centrally configure cryptographic polices. The command update-crypto-policies is used to set the policy applicable for the various cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic policies will be the default policy used by these backends unless the application user configures them otherwise. When the system has been configured to use the centralized cryptographic policies, the administrator is assured that any application that utilizes the supported backends will follow a policy that adheres to the configured profile. Currently the supported backends are:
  • GnuTLS library
  • OpenSSL library
  • NSS library
  • OpenJDK
  • Libkrb5
  • BIND
  • OpenSSH
Applications and languages which rely on any of these backends will follow the system policies as well. Examples are apache httpd, nginx, php, and others.

Rule   Configure BIND to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. BIND is supported by crypto policy, but the BIND configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the /etc/named.conf includes the appropriate configuration: In the options section of /etc/named.conf, make sure that the following line is not commented out or superseded by later includes: include "/etc/crypto-policies/back-ends/bind.config";
Rationale:
Overriding the system crypto policy makes the behavior of the BIND service violate expectations, and makes system configuration more fragmented.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_configure_bind_crypto_policy
Identifiers and References

References:  CIP-003-8 R4.2, CIP-007-3 R5.1, SC-13, SC-12(2), SC-12(3), SRG-OS-000423-GPOS-00187, SRG-OS-000426-GPOS-00190



function remediate_bind_crypto_policy() {
	CONFIG_FILE="/etc/named.conf"
	if test -f "$CONFIG_FILE"; then
		sed -i 's|options {|&\n\tinclude "/etc/crypto-policies/back-ends/bind.config";|' "$CONFIG_FILE"
		return 0
	else
		echo "Aborting remediation as '$CONFIG_FILE' was not even found." >&2
		return 1
	fi
}

remediate_bind_crypto_policy

Rule   Configure System Cryptography Policy   [ref]

To configure the system cryptography policy to use ciphers only from the DEFAULT policy, run the following command:
$ sudo update-crypto-policies --set DEFAULT
The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the /etc/crypto-policies/back-ends are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied. Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon.
Warning:  The system needs to be rebooted for these changes to take effect.
Warning:  System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.
Rationale:
Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_configure_crypto_policy
Identifiers and References

References:  164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii), 1446, CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), FCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), FCS_CKM.1, FCS_CKM.2, FCS_TLSC_EXT.1, SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
        - name: configure-crypto-policy.service
          enabled: true
          contents: |
            [Unit]
            Before=kubelet.service
            [Service]
            Type=oneshot
            ExecStart=update-crypto-policies --set {{.var_system_crypto_policy}}
            RemainAfterExit=yes
            [Install]
            WantedBy=multi-user.target

Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_system_crypto_policy # promote to variable
  set_fact:
    var_system_crypto_policy: !!str DEFAULT
  tags:
    - always

- name: Configure System Cryptography Policy
  lineinfile:
    path: /etc/crypto-policies/config
    regexp: ^(?!#)(\S+)$
    line: '{{ var_system_crypto_policy }}'
    create: true
  tags:
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - configure_crypto_policy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy

- name: Verify that Crypto Policy is Set (runtime)
  command: /usr/bin/update-crypto-policies --set {{ var_system_crypto_policy }}
  tags:
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - configure_crypto_policy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy


var_system_crypto_policy='DEFAULT'


stderr_of_call=$(update-crypto-policies --set ${var_system_crypto_policy} 2>&1 > /dev/null)
rc=$?

if test "$rc" = 127; then
	echo "$stderr_of_call" >&2
	echo "Make sure that the script is installed on the remediated system." >&2
	echo "See output of the 'dnf provides update-crypto-policies' command" >&2
	echo "to see what package to (re)install" >&2

	false  # end with an error code
elif test "$rc" != 0; then
	echo "Error invoking the update-crypto-policies script: $stderr_of_call" >&2
	false  # end with an error code
fi

Rule   Configure GnuTLS library to use DoD-approved TLS Encryption   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. GnuTLS is supported by system crypto policy, but the GnuTLS configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that /etc/crypto-policies/back-ends/gnutls.config contains the following line and is not commented out: +VERS-ALL:-VERS-DTLS0.9:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS1.0
Rationale:
Overriding the system crypto policy makes the behavior of the GnuTLS library violate expectations, and makes system configuration more fragmented.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_gnutls_tls_crypto_policy
Identifiers and References

References:  CCI-001453, AC-17(2), SRG-OS-000250-GPOS-00093, SRG-OS-000423-GPOS-00187


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: 'Configure GnuTLS library to use DoD-approved TLS Encryption: set_fact'
  set_fact:
    path: /etc/crypto-policies/back-ends/gnutls.config
    correct_value: +VERS-ALL:-VERS-DTLS0.9:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS1.0
    lineinfile_reg: \+VERS-ALL:-VERS-DTLS0\.9:-VERS-SSL3\.0:-VERS-TLS1\.0:-VERS-TLS1\.1:-VERS-DTLS1\.0
  tags:
  - NIST-800-53-AC-17(2)
  - configure_gnutls_tls_crypto_policy
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: 'Configure GnuTLS library to use DoD-approved TLS Encryption: stat'
  stat:
    path: '{{ path }}'
    follow: true
  register: gnutls_file
  tags:
  - NIST-800-53-AC-17(2)
  - configure_gnutls_tls_crypto_policy
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: 'Configure GnuTLS library to use DoD-approved TLS Encryption: Add'
  lineinfile:
    path: '{{ path }}'
    regexp: '{{ lineinfile_reg }}'
    line: '{{ correct_value }}'
    create: true
  when: not gnutls_file.stat.exists or gnutls_file.stat.size <= correct_value|length
  tags:
  - NIST-800-53-AC-17(2)
  - configure_gnutls_tls_crypto_policy
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Configure GnuTLS library to use DoD-approved TLS Encryption
  block:

  - name: 'Configure GnuTLS library to use DoD-approved TLS Encryption: Existing value
      check'
    lineinfile:
      path: '{{ path }}'
      create: false
      regexp: '{{ lineinfile_reg }}'
      state: absent
    check_mode: true
    changed_when: false
    register: gnutls

  - name: 'Configure GnuTLS library to use DoD-approved TLS Encryption: Update'
    replace:
      path: '{{ path }}'
      regexp: (\+VERS-ALL(?::-VERS-[A-Z]+\d\.\d)+)
      replace: '{{ correct_value }}'
    when: gnutls.found is defined and gnutls.found != 1
  when: gnutls_file.stat.exists and gnutls_file.stat.size > correct_value|length
  tags:
  - NIST-800-53-AC-17(2)
  - configure_gnutls_tls_crypto_policy
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict

CONF_FILE=/etc/crypto-policies/back-ends/gnutls.config
correct_value='+VERS-ALL:-VERS-DTLS0.9:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS1.0'

grep -q ${correct_value} ${CONF_FILE}

if [[ $? -ne 0 ]]; then
    # We need to get the existing value, using PCRE to maintain same regex
    existing_value=$(grep -Po '(\+VERS-ALL(?::-VERS-[A-Z]+\d\.\d)+)' ${CONF_FILE})

    if [[ ! -z ${existing_value} ]]; then
        # replace existing_value with correct_value
        sed -i "s/${existing_value}/${correct_value}/g" ${CONF_FILE}
    else
        # ***NOTE*** #
        # This probably means this file is not here or it's been modified
        # unintentionally.
        # ********** #
        # echo correct_value to end
        echo ${correct_value} >> ${CONF_FILE}
    fi
fi

Rule   Configure Kerberos to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. Kerberos is supported by crypto policy, but it's configuration may be set up to ignore it. To check that Crypto Policies settings for Kerberos are configured correctly, examine that there is a symlink at /etc/krb5.conf.d/crypto-policies targeting /etc/cypto-policies/back-ends/krb5.config. If the symlink exists, Kerberos is configured to use the system-wide crypto policy settings.
Rationale:
Overriding the system crypto policy makes the behavior of Kerberos violate expectations, and makes system configuration more fragmented.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_configure_kerberos_crypto_policy
Identifiers and References

References:  0418, 1055, 1402, CIP-003-8 R4.2, CIP-007-3 R5.1, SC-13, SC-12(2), SC-12(3), SRG-OS-000120-GPOS-00061


Complexity:low
Disruption:low
Reboot:true
Strategy:configure
- name: Configure Kerberos to use System Crypto Policy
  file:
    src: /etc/crypto-policies/back-ends/krb5.config
    path: /etc/krb5.conf.d/crypto-policies
    state: link
  tags:
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - configure_kerberos_crypto_policy
  - configure_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - reboot_required

Complexity:low
Disruption:low
Reboot:true
Strategy:configure

rm -f /etc/krb5.conf.d/crypto-policies
ln -s /etc/crypto-policies/back-ends/krb5.config /etc/krb5.conf.d/crypto-policies

Rule   Configure Libreswan to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. Libreswan is supported by system crypto policy, but the Libreswan configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the /etc/ipsec.conf includes the appropriate configuration file. In /etc/ipsec.conf, make sure that the following line is not commented out or superseded by later includes: include /etc/crypto-policies/back-ends/libreswan.config
Rationale:
Overriding the system crypto policy makes the behavior of the Libreswan service violate expectations, and makes system configuration more fragmented.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_configure_libreswan_crypto_policy
Identifiers and References

References:  CIP-003-8 R4.2, CIP-007-3 R5.1, CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), FCS_IPSEC_EXT.1.4, FCS_IPSEC_EXT.1.6, Req-2.2, 2.2, SRG-OS-000033-GPOS-00014


Complexity:low
Disruption:low
Strategy:restrict
- name: Configure Libreswan to use System Crypto Policy
  lineinfile:
    path: /etc/ipsec.conf
    line: include /etc/crypto-policies/back-ends/libreswan.config
    create: true
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - PCI-DSS-Req-2.2
  - PCI-DSSv4-2.2
  - configure_libreswan_crypto_policy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy


function remediate_libreswan_crypto_policy() {
    CONFIG_FILE="/etc/ipsec.conf"
    if ! grep -qP "^\s*include\s+/etc/crypto-policies/back-ends/libreswan.config\s*(?:#.*)?$" "$CONFIG_FILE" ; then
        # the file might not end with a new line
        echo -e '\ninclude /etc/crypto-policies/back-ends/libreswan.config' >> "$CONFIG_FILE"
    fi
    return 0
}

remediate_libreswan_crypto_policy

Rule   Configure OpenSSL library to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. OpenSSL is supported by crypto policy, but the OpenSSL configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, you have to examine the OpenSSL config file available under /etc/pki/tls/openssl.cnf. This file has the ini format, and it enables crypto policy support if there is a [ crypto_policy ] section that contains the .include = /etc/crypto-policies/back-ends/opensslcnf.config directive.
Rationale:
Overriding the system crypto policy makes the behavior of the Java runtime violates expectations, and makes system configuration more fragmented.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_openssl_crypto_policy
Identifiers and References

References:  CCI-001453, CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), Req-2.2, 2.2, SRG-OS-000250-GPOS-00093


Complexity:low
Disruption:medium
- name: Test for crypto_policy group
  command: grep '^\s*\[\s*crypto_policy\s*]' /etc/pki/tls/openssl.cnf
  register: test_crypto_policy_group
  failed_when: test_crypto_policy_group.rc not in [0, 1]
  changed_when: false
  check_mode: false
  tags:
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - PCI-DSS-Req-2.2
  - PCI-DSSv4-2.2
  - configure_openssl_crypto_policy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Add .include for opensslcnf.config to crypto_policy section
  lineinfile:
    create: true
    insertafter: ^\s*\[\s*crypto_policy\s*]\s*
    line: .include = /etc/crypto-policies/back-ends/opensslcnf.config
    path: /etc/pki/tls/openssl.cnf
  when:
  - test_crypto_policy_group.stdout is defined
  - test_crypto_policy_group.stdout | length > 0
  tags:
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - PCI-DSS-Req-2.2
  - PCI-DSSv4-2.2
  - configure_openssl_crypto_policy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy

- name: Add crypto_policy group and set include opensslcnf.config
  lineinfile:
    create: true
    line: |-
      [crypto_policy]
      .include = /etc/crypto-policies/back-ends/opensslcnf.config
    path: /etc/pki/tls/openssl.cnf
  when:
  - test_crypto_policy_group.stdout is defined
  - test_crypto_policy_group.stdout | length < 1
  tags:
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-12(2)
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SC-13
  - PCI-DSS-Req-2.2
  - PCI-DSSv4-2.2
  - configure_openssl_crypto_policy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - unknown_strategy


OPENSSL_CRYPTO_POLICY_SECTION='[ crypto_policy ]'
OPENSSL_CRYPTO_POLICY_SECTION_REGEX='\[\s*crypto_policy\s*\]'
OPENSSL_CRYPTO_POLICY_INCLUSION='.include = /etc/crypto-policies/back-ends/opensslcnf.config'
OPENSSL_CRYPTO_POLICY_INCLUSION_REGEX='^\s*\.include\s*(?:=\s*)?/etc/crypto-policies/back-ends/opensslcnf.config$'


  


function remediate_openssl_crypto_policy() {
	CONFIG_FILE=/etc/pki/tls/openssl.cnf
	if test -f "$CONFIG_FILE"; then
		if ! grep -q "^\\s*$OPENSSL_CRYPTO_POLICY_SECTION_REGEX" "$CONFIG_FILE"; then
			printf '\n%s\n\n%s' "$OPENSSL_CRYPTO_POLICY_SECTION" "$OPENSSL_CRYPTO_POLICY_INCLUSION" >> "$CONFIG_FILE"
			return 0
		elif ! grep -q "^\\s*$OPENSSL_CRYPTO_POLICY_INCLUSION_REGEX" "$CONFIG_FILE"; then
			sed -i "s|$OPENSSL_CRYPTO_POLICY_SECTION_REGEX|&\\n\\n$OPENSSL_CRYPTO_POLICY_INCLUSION\\n|" "$CONFIG_FILE"
			return 0
		fi
	else
		echo "Aborting remediation as '$CONFIG_FILE' was not even found." >&2
		return 1
	fi
}

remediate_openssl_crypto_policy

Rule   Configure SSH to use System Crypto Policy   [ref]

Crypto Policies provide a centralized control over crypto algorithms usage of many packages. SSH is supported by crypto policy, but the SSH configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the CRYPTO_POLICY variable is either commented or not set at all in the /etc/sysconfig/sshd.
Rationale:
Overriding the system crypto policy makes the behavior of the SSH service violate expectations, and makes system configuration more fragmented.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_ssh_crypto_policy
Identifiers and References

References:  CCI-001453, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii), CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, FCS_SSH_EXT.1, FCS_SSHS_EXT.1, FCS_SSHC_EXT.1, Req-2.2, 2.2, SRG-OS-000250-GPOS-00093


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Configure SSH to use System Crypto Policy
  lineinfile:
    dest: /etc/sysconfig/sshd
    state: absent
    regexp: ^\s*(?i)CRYPTO_POLICY.*$
  tags:
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-13
  - PCI-DSS-Req-2.2
  - PCI-DSSv4-2.2
  - configure_ssh_crypto_policy
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required


SSH_CONF="/etc/sysconfig/sshd"

sed -i "/^\s*CRYPTO_POLICY.*$/Id" $SSH_CONF
Group   GNOME Desktop Environment   Group contains 1 group and 2 rules
[ref]   GNOME is a graphical desktop environment bundled with many Linux distributions that allow users to easily interact with the operating system graphically rather than textually. The GNOME Graphical Display Manager (GDM) provides login, logout, and user switching contexts as well as display server management.

GNOME is developed by the GNOME Project and is considered the default Red Hat Graphical environment.

For more information on GNOME and the GNOME Project, see https://www.gnome.org.
Group   Configure GNOME Login Screen   Group contains 2 rules

Rule   Disable XDMCP in GDM   [ref]

XDMCP is an unencrypted protocol, and therefore, presents a security risk, see e.g. XDMCP Gnome docs. To disable XDMCP support in Gnome, set Enable to false under the [xdmcp] configuration section in /etc/gdm/custom.conf. For example:
[xdmcp]
Enable=false
Rationale:
XDMCP provides unencrypted remote access through the Gnome Display Manager (GDM) which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using XDMCP, the privileged user password could be compromised due to typed XEvents and keystrokes will traversing over the network in clear text.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_gnome_gdm_disable_xdmcp
Identifiers and References

Complexity:low
Disruption:medium
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - gnome_gdm_disable_xdmcp
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed
  - unknown_strategy

- name: Disable XDMCP in GDM
  ini_file:
    path: /etc/gdm/custom.conf
    section: xdmcp
    option: Enable
    value: 'false'
    create: true
    mode: 420
  when: '"gdm" in ansible_facts.packages'
  tags:
  - gnome_gdm_disable_xdmcp
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed
  - unknown_strategy

# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then

# Try find '[xdmcp]' and 'Enable' in '/etc/gdm/custom.conf', if it exists, set
# to 'false', if it isn't here, add it, if '[xdmcp]' doesn't exist, add it there
if grep -qzosP '[[:space:]]*\[xdmcp]([^\n\[]*\n+)+?[[:space:]]*Enable' '/etc/gdm/custom.conf'; then
    
    sed -i "s/Enable[^(\n)]*/Enable=false/" '/etc/gdm/custom.conf'
elif grep -qs '[[:space:]]*\[xdmcp]' '/etc/gdm/custom.conf'; then
    sed -i "/[[:space:]]*\[xdmcp]/a Enable=false" '/etc/gdm/custom.conf'
else
    if test -d "/etc/gdm"; then
        printf '%s\n' '[xdmcp]' "Enable=false" >> '/etc/gdm/custom.conf'
    else
        echo "Config file directory '/etc/gdm' doesnt exist, not remediating, assuming non-applicability." >&2
    fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Sudo   Group contains 6 rules
[ref]   Sudo, which stands for "su 'do'", provides the ability to delegate authority to certain users, groups of users, or system administrators. When configured for system users and/or groups, Sudo can allow a user or group to execute privileged commands that normally only root is allowed to execute.

For more information on Sudo and addition Sudo configuration options, see https://www.sudo.ws.

Rule   Install sudo Package   [ref]

The sudo package can be installed with the following command:
$ sudo dnf install sudo
Rationale:
sudo is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_sudo_installed
Identifiers and References

References:  BP28(R19), 1382, 1384, 1386, CM-6(a), FMT_MOF_EXT.1, 10.2.1.5, SRG-OS-000324-GPOS-00125


Complexity:low
Disruption:low
Strategy:enable

package --add=sudo


[[packages]]
name = "sudo"
version = "*"

Complexity:low
Disruption:low
Strategy:enable
include install_sudo

class install_sudo {
  package { 'sudo':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure sudo is installed
  package:
    name: sudo
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-10.2.1.5
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_sudo_installed

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if ! rpm -q --quiet "sudo" ; then
    dnf install -y "sudo"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty   [ref]

The sudo use_pty tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by making sure that the use_pty tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
Requiring that sudo commands be run in a pseudo-terminal can prevent an attacker from retaining access to the user's terminal after the main program has finished executing.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_use_pty
Identifiers and References

References:  BP28(R58), Req-10.2.5, 10.2.1.5


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_use_pty

- name: Ensure use_pty is enabled in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults.*\buse_pty\b.*$
    line: Defaults use_pty
    validate: /usr/sbin/visudo -cf %s
  when: '"sudo" in ansible_facts.packages'
  tags:
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_use_pty

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q sudo; then

if /usr/sbin/visudo -qcf /etc/sudoers; then
    cp /etc/sudoers /etc/sudoers.bak
    if ! grep -P '^[\s]*Defaults[\s]*\buse_pty\b.*$' /etc/sudoers; then
        # sudoers file doesn't define Option use_pty
        echo "Defaults use_pty" >> /etc/sudoers
    fi
    
    # Check validity of sudoers and cleanup bak
    if /usr/sbin/visudo -qcf /etc/sudoers; then
        rm -f /etc/sudoers.bak
    else
        echo "Fail to validate remediated /etc/sudoers, reverting to original file."
        mv /etc/sudoers.bak /etc/sudoers
        false
    fi
else
    echo "Skipping remediation, /etc/sudoers failed to validate"
    false
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure Sudo Logfile Exists - sudo logfile   [ref]

A custom log sudo file can be configured with the 'logfile' tag. This rule configures a sudo custom logfile at the default location suggested by CIS, which uses /var/log/sudo.log.
Rationale:
A sudo log file simplifies auditing of sudo commands.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_sudo_custom_logfile
Identifiers and References

References:  Req-10.2.5, 10.2.1.5


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_custom_logfile
- name: XCCDF Value var_sudo_logfile # promote to variable
  set_fact:
    var_sudo_logfile: !!str /var/log/sudo.log
  tags:
    - always

- name: Ensure logfile is enabled with the appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults\s(.*)\blogfile=[-]?.+\b(.*)$
    line: Defaults \1logfile={{ var_sudo_logfile }}\2
    validate: /usr/sbin/visudo -cf %s
    backrefs: true
  register: edit_sudoers_logfile_option
  when: '"sudo" in ansible_facts.packages'
  tags:
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_custom_logfile

- name: Enable logfile option with appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    line: Defaults logfile={{ var_sudo_logfile }}
    validate: /usr/sbin/visudo -cf %s
  when:
  - '"sudo" in ansible_facts.packages'
  - edit_sudoers_logfile_option is defined and not edit_sudoers_logfile_option.changed
  tags:
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_custom_logfile

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q sudo; then

var_sudo_logfile='/var/log/sudo.log'


if /usr/sbin/visudo -qcf /etc/sudoers; then
    cp /etc/sudoers /etc/sudoers.bak
    if ! grep -P '^[\s]*Defaults[\s]*\blogfile=("(?:\\"|\\\\|[^"\\\n])*"\B|[^"](?:(?:\\,|\\"|\\ |\\\\|[^", \\\n])*)\b)\b.*$' /etc/sudoers; then
        # sudoers file doesn't define Option logfile
        echo "Defaults logfile=${var_sudo_logfile}" >> /etc/sudoers
    else
        # sudoers file defines Option logfile, remediate if appropriate value is not set
        if ! grep -P "^[\s]*Defaults.*\blogfile=${var_sudo_logfile}\b.*$" /etc/sudoers; then
            
            escaped_variable=${var_sudo_logfile//$'/'/$'\/'}
            sed -Ei "s/(^[\s]*Defaults.*\blogfile=)[-]?.+(\b.*$)/\1$escaped_variable\2/" /etc/sudoers
        fi
    fi
    
    # Check validity of sudoers and cleanup bak
    if /usr/sbin/visudo -qcf /etc/sudoers; then
        rm -f /etc/sudoers.bak
    else
        echo "Fail to validate remediated /etc/sudoers, reverting to original file."
        mv /etc/sudoers.bak /etc/sudoers
        false
    fi
else
    echo "Skipping remediation, /etc/sudoers failed to validate"
    false
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure Users Re-Authenticate for Privilege Escalation - sudo   [ref]

The sudo NOPASSWD and !authenticate option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that NOPASSWD and/or !authenticate do not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/."
Rationale:
Without re-authentication, users may access resources or perform tasks for which they do not have authorization.

When operating systems provide the capability to escalate a functional capability, it is critical that the user re-authenticate.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_require_authentication
Identifiers and References

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.10, DSS06.03, DSS06.10, CCI-002038, 4.3.3.5.1, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-11, CM-6(a), PR.AC-1, PR.AC-7, SRG-OS-000373-GPOS-00156


Complexity:low
Disruption:low
Strategy:restrict
- name: Find /etc/sudoers.d/ files
  find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

- name: Remove lines containing NOPASSWD from sudoers files
  replace:
    regexp: (^(?!#).*[\s]+NOPASSWD[\s]*\:.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

- name: Find /etc/sudoers.d/ files
  find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

- name: Remove lines containing !authenticate from sudoers files
  replace:
    regexp: (^(?!#).*[\s]+\!authenticate.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_authentication

Complexity:low
Disruption:low
Strategy:restrict

for f in /etc/sudoers /etc/sudoers.d/* ; do
  if [ ! -e "$f" ] ; then
    continue
  fi
  matching_list=$(grep -P '^(?!#).*[\s]+NOPASSWD[\s]*\:.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      # comment out "NOPASSWD" matches to preserve user data
      sed -i "s/^${entry}$/# &/g" $f
    done <<< "$matching_list"

    /usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
  fi
done

for f in /etc/sudoers /etc/sudoers.d/* ; do
  if [ ! -e "$f" ] ; then
    continue
  fi
  matching_list=$(grep -P '^(?!#).*[\s]+\!authenticate.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      # comment out "!authenticate" matches to preserve user data
      sed -i "s/^${entry}$/# &/g" $f
    done <<< "$matching_list"

    /usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
  fi
done

Rule   Require Re-Authentication When Using the sudo Command   [ref]

The sudo timestamp_timeout tag sets the amount of time sudo password prompt waits. The default timestamp_timeout value is 5 minutes. The timestamp_timeout should be configured by making sure that the timestamp_timeout tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/. If the value is set to an integer less than 0, the user's time stamp will not expire and the user will not have to re-authenticate for privileged actions until the user's session is terminated.
Rationale:
Without re-authentication, users may access resources or perform tasks for which they do not have authorization.

When operating systems provide the capability to escalate a functional capability, it is critical that the user re-authenticate.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_require_reauthentication
Identifiers and References

References:  CCI-002038, IA-11, SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_reauthentication
- name: XCCDF Value var_sudo_timestamp_timeout # promote to variable
  set_fact:
    var_sudo_timestamp_timeout: !!str 5
  tags:
    - always

- name: Find out if /etc/sudoers.d/* files contain 'Defaults timestamp_timeout' to
    be deduplicated
  find:
    path: /etc/sudoers.d
    patterns: '*'
    contains: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=.*
  register: sudoers_d_defaults_timestamp_timeout
  when: '"sudo" in ansible_facts.packages'
  tags:
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_reauthentication

- name: Remove found occurrences of 'Defaults timestamp_timeout' from /etc/sudoers.d/*
    files
  lineinfile:
    path: '{{ item.path }}'
    regexp: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=.*
    state: absent
  with_items: '{{ sudoers_d_defaults_timestamp_timeout.files }}'
  when: '"sudo" in ansible_facts.packages'
  tags:
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_reauthentication

- name: Ensure timestamp_timeout is enabled with the appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults\s(.*)\btimestamp_timeout[\s]*=[\s]*[-]?\w+\b(.*)$
    line: Defaults \1timestamp_timeout={{ var_sudo_timestamp_timeout }}\2
    validate: /usr/sbin/visudo -cf %s
    backrefs: true
  register: edit_sudoers_timestamp_timeout_option
  when: '"sudo" in ansible_facts.packages'
  tags:
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_reauthentication

- name: Enable timestamp_timeout option with appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    line: Defaults timestamp_timeout={{ var_sudo_timestamp_timeout }}
    validate: /usr/sbin/visudo -cf %s
  when:
  - '"sudo" in ansible_facts.packages'
  - edit_sudoers_timestamp_timeout_option is defined and not edit_sudoers_timestamp_timeout_option.changed
  tags:
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_require_reauthentication

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q sudo; then

var_sudo_timestamp_timeout='5'


if grep -Px '^[\s]*Defaults.*timestamp_timeout[\s]*=.*' /etc/sudoers.d/*; then
    find /etc/sudoers.d/ -type f -exec sed -Ei "/^[[:blank:]]*Defaults.*timestamp_timeout[[:blank:]]*=.*/d" {} \;
fi

if /usr/sbin/visudo -qcf /etc/sudoers; then
    cp /etc/sudoers /etc/sudoers.bak
    if ! grep -P '^[\s]*Defaults.*timestamp_timeout[\s]*=[\s]*[-]?\w+.*$' /etc/sudoers; then
        # sudoers file doesn't define Option timestamp_timeout
        echo "Defaults timestamp_timeout=${var_sudo_timestamp_timeout}" >> /etc/sudoers
    else
        # sudoers file defines Option timestamp_timeout, remediate if appropriate value is not set
        if ! grep -P "^[\s]*Defaults.*timestamp_timeout[\s]*=[\s]*${var_sudo_timestamp_timeout}.*$" /etc/sudoers; then
            
            sed -Ei "s/(^[[:blank:]]*Defaults.*timestamp_timeout[[:blank:]]*=)[[:blank:]]*[-]?\w+(.*$)/\1${var_sudo_timestamp_timeout}\2/" /etc/sudoers
        fi
    fi
    
    # Check validity of sudoers and cleanup bak
    if /usr/sbin/visudo -qcf /etc/sudoers; then
        rm -f /etc/sudoers.bak
    else
        echo "Fail to validate remediated /etc/sudoers, reverting to original file."
        mv /etc/sudoers.bak /etc/sudoers
        false
    fi
else
    echo "Skipping remediation, /etc/sudoers failed to validate"
    false
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure sudo only includes the default configuration directory   [ref]

Administrators can configure authorized sudo users via drop-in files, and it is possible to include other directories and configuration files from the file currently being parsed. Make sure that /etc/sudoers only includes drop-in configuration files from /etc/sudoers.d, or that no drop-in file is included. Either the /etc/sudoers should contain only one #includedir directive pointing to /etc/sudoers.d, and no file in /etc/sudoers.d/ should include other files or directories; Or the /etc/sudoers should not contain any #include, @include, #includedir or @includedir directives. Note that the '#' character doesn't denote a comment in the configuration file.
Rationale:
Some sudo configurtion options allow users to run programs without re-authenticating. Use of these configuration options makes it easier for one compromised accound to be used to compromise other accounts.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudoers_default_includedir
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Check for duplicate values
  lineinfile:
    path: /etc/sudoers
    create: false
    regexp: ^#includedir.*$
    state: absent
  check_mode: true
  changed_when: false
  register: dupes
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir

- name: Deduplicate values from /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    create: false
    regexp: ^#includedir.*$
    state: absent
  when: dupes.found is defined and dupes.found > 1
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir

- name: Insert correct line into /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    create: false
    regexp: ^#includedir.*$
    line: '#includedir /etc/sudoers.d'
    state: present
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir

- name: Ensure sudoers doesn't include other non-default file
  lineinfile:
    path: /etc/sudoers
    create: false
    regexp: ^[#@]include[\s]+.*$
    state: absent
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir

- name: Ensure sudoers doesn't have non-default includedir
  lineinfile:
    path: /etc/sudoers
    create: false
    regexp: ^@includedir[\s]+.*$
    state: absent
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir

- name: Find out if /etc/sudoers.d/* files contain file or directory includes
  find:
    path: /etc/sudoers.d
    patterns: '*'
    contains: ^[#@]include(dir)?\s.*$
  register: sudoers_d_includes
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir

- name: Remove found occurrences of file and directory includes from /etc/sudoers.d/*
    files
  lineinfile:
    path: '{{ item.path }}'
    regexp: ^[#@]include(dir)?\s.*$
    state: absent
  with_items: '{{ sudoers_d_includes.files }}'
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sudoers_default_includedir


sudoers_config_file="/etc/sudoers"
sudoers_config_dir="/etc/sudoers.d"
sudoers_includedir_count=$(grep -c "#includedir" "$sudoers_config_file")
if [ "$sudoers_includedir_count" -gt 1 ]; then
    sed -i "/#includedir/d" "$sudoers_config_file"
    echo "#includedir /etc/sudoers.d" >> "$sudoers_config_file"
elif [ "$sudoers_includedir_count" -eq 0 ]; then
    echo "#includedir /etc/sudoers.d" >> "$sudoers_config_file"
else
    if ! grep -q "^#includedir /etc/sudoers.d" "$sudoers_config_file"; then
        sed -i "s|^#includedir.*|#includedir /etc/sudoers.d|g" "$sudoers_config_file"
    fi
fi

sed -Ei "/^#include\s/d; /^@includedir\s/d" "$sudoers_config_file"

if grep -Pr "^[#@]include(dir)?\s" "$sudoers_config_dir" ; then
    sed -Ei "/^[#@]include(dir)?\s/d" "$sudoers_config_dir"/*
fi
Group   Updating Software   Group contains 1 rule
[ref]   The dnf command line tool is used to install and update software packages. The system also provides a graphical software update tool in the System menu, in the Administration submenu, called Software Update.

Fedora systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using dnf or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.

Rule   Install GNOME Software   [ref]

The gnome-software package can be installed with the following command:
$ sudo dnf install gnome-software
Rationale:
The GNOME software package must be installed so that it can be used for software and firmware updates.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_gnome_software_installed
Identifiers and References

Complexity:low
Disruption:low
Strategy:enable

package --add=gnome-software


[[packages]]
name = "gnome-software"
version = "*"

Complexity:low
Disruption:low
Strategy:enable
include install_gnome-software

class install_gnome-software {
  package { 'gnome-software':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure gnome-software is installed
  package:
    name: gnome-software
    state: present
  tags:
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_gnome_software_installed

Complexity:low
Disruption:low
Strategy:enable

if ! rpm -q --quiet "gnome-software" ; then
    dnf install -y "gnome-software"
fi
Group   Account and Access Control   Group contains 12 groups and 32 rules
[ref]   In traditional Unix security, if an attacker gains shell access to a certain login account, they can perform any action or access any file to which that account has access. Therefore, making it more difficult for unauthorized people to gain shell access to accounts, particularly to privileged accounts, is a necessary part of securing a system. This section introduces mechanisms for restricting access to accounts under Fedora.
Group   Protect Accounts by Configuring PAM   Group contains 4 groups and 11 rules
[ref]   PAM, or Pluggable Authentication Modules, is a system which implements modular authentication for Linux programs. PAM provides a flexible and configurable architecture for authentication, and it should be configured to minimize exposure to unnecessary risk. This section contains guidance on how to accomplish that.

PAM is implemented as a set of shared objects which are loaded and invoked whenever an application wishes to authenticate a user. Typically, the application must be running as root in order to take advantage of PAM, because PAM's modules often need to be able to access sensitive stores of account information, such as /etc/shadow. Traditional privileged network listeners (e.g. sshd) or SUID programs (e.g. sudo) already meet this requirement. An SUID root application, userhelper, is provided so that programs which are not SUID or privileged themselves can still take advantage of PAM.

PAM looks in the directory /etc/pam.d for application-specific configuration information. For instance, if the program login attempts to authenticate a user, then PAM's libraries follow the instructions in the file /etc/pam.d/login to determine what actions should be taken.

One very important file in /etc/pam.d is /etc/pam.d/system-auth. This file, which is included by many other PAM configuration files, defines 'default' system authentication measures. Modifying this file is a good way to make far-reaching authentication changes, for instance when implementing a centralized authentication service.
Warning:  Be careful when making changes to PAM's configuration files. The syntax for these files is complex, and modifications can have unexpected consequences. The default configurations shipped with applications should be sufficient for most users.
Warning:  Running authconfig or system-config-authentication will re-write the PAM configuration files, destroying any manually made changes and replacing them with a series of system defaults. One reference to the configuration file syntax can be found at https://fossies.org/linux/Linux-PAM-docs/doc/sag/Linux-PAM_SAG.pdf.
Group   Set Lockouts for Failed Password Attempts   Group contains 1 rule
[ref]   The pam_faillock PAM module provides the capability to lock out user accounts after a number of failed login attempts. Its documentation is available in /usr/share/doc/pam-VERSION/txts/README.pam_faillock.

Warning:  Locking out user accounts presents the risk of a denial-of-service attack. The lockout policy must weigh whether the risk of such a denial-of-service attack outweighs the benefits of thwarting password guessing attacks.
Group   Set Password Quality Requirements   Group contains 1 group and 7 rules
[ref]   The default pam_pwquality PAM module provides strength checking for passwords. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of at least a certain length, are not the previous password reversed, and are not simply a change of case from the previous password. It can also require passwords to be in certain character classes. The pam_pwquality module is the preferred way of configuring password requirements.

The man pages pam_pwquality(8) provide information on the capabilities and configuration of each.
Group   Set Password Quality Requirements with pam_pwquality   Group contains 7 rules
[ref]   The pam_pwquality PAM module can be configured to meet requirements for a variety of policies.

For example, to configure pam_pwquality to require at least one uppercase character, lowercase character, digit, and other (special) character, make sure that pam_pwquality exists in /etc/pam.d/system-auth:
password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth. Next, modify the settings in /etc/security/pwquality.conf to match the following:
difok = 4
minlen = 14
dcredit = -1
ucredit = -1
lcredit = -1
ocredit = -1
maxrepeat = 3
The arguments can be modified to ensure compliance with your organization's security policy. Discussion of each parameter follows.

Rule   Ensure PAM Enforces Password Requirements - Minimum Different Characters   [ref]

The pam_pwquality module's difok parameter sets the number of characters in a password that must not be present in and old password during a password change.

Modify the difok setting in /etc/security/pwquality.conf to equal 8 to require differing characters when changing passwords.
Rationale:
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute–force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Requiring a minimum number of different characters during password changes ensures that newly changed passwords should not resemble previously compromised ones. Note that passwords which are changed on compromised systems will still be compromised, however.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_difok
Identifiers and References

References:  1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(b), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.1.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_difok # promote to variable
  set_fact:
    var_password_pam_difok: !!str 8
  tags:
    - always

- name: Ensure PAM Enforces Password Requirements - Minimum Different Characters -
    Ensure PAM variable difok is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*difok
    line: difok = {{ var_password_pam_difok }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.1.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(b)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - accounts_password_pam_difok
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_difok='8'






# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^difok")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_difok"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^difok\\>" "/etc/security/pwquality.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^difok\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
    if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set Password Maximum Consecutive Repeating Characters   [ref]

The pam_pwquality module's maxrepeat parameter controls requirements for consecutive repeating characters. When set to a positive number, it will reject passwords which contain more than that number of consecutive characters. Modify the maxrepeat setting in /etc/security/pwquality.conf to equal 3 to prevent a run of (3 + 1) or more identical characters.
Rationale:
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Passwords with excessive repeating characters may be more vulnerable to password-guessing attacks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_maxrepeat
Identifiers and References

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - accounts_password_pam_maxrepeat
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_maxrepeat # promote to variable
  set_fact:
    var_password_pam_maxrepeat: !!str 3
  tags:
    - always

- name: Set Password Maximum Consecutive Repeating Characters - Ensure PAM variable
    maxrepeat is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*maxrepeat
    line: maxrepeat = {{ var_password_pam_maxrepeat }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - accounts_password_pam_maxrepeat
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_maxrepeat='3'






# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^maxrepeat")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_maxrepeat"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^maxrepeat\\>" "/etc/security/pwquality.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^maxrepeat\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
    if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure PAM Enforces Password Requirements - Minimum Different Categories   [ref]

The pam_pwquality module's minclass parameter controls requirements for usage of different character classes, or types, of character that must exist in a password before it is considered valid. For example, setting this value to three (3) requires that any password must have characters from at least three different categories in order to be approved. The default value is zero (0), meaning there are no required classes. There are four categories available:
* Upper-case characters
* Lower-case characters
* Digits
* Special characters (for example, punctuation)
Modify the minclass setting in /etc/security/pwquality.conf entry to require 3 differing categories of characters when changing passwords.
Rationale:
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Requiring a minimum number of character categories makes password guessing attacks more difficult by ensuring a larger search space.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_minclass
Identifiers and References

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - accounts_password_pam_minclass
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_minclass # promote to variable
  set_fact:
    var_password_pam_minclass: !!str 3
  tags:
    - always

- name: Ensure PAM Enforces Password Requirements - Minimum Different Categories -
    Ensure PAM variable minclass is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*minclass
    line: minclass = {{ var_password_pam_minclass }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - accounts_password_pam_minclass
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_minclass='3'






# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^minclass")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_minclass"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^minclass\\>" "/etc/security/pwquality.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^minclass\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
    if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure PAM Enforces Password Requirements - Minimum Length   [ref]

The pam_pwquality module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=15 after pam_pwquality to set minimum password length requirements.
Rationale:
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000205, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, 8.3.9, SRG-OS-000078-GPOS-00046


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.1.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_minlen # promote to variable
  set_fact:
    var_password_pam_minlen: !!str 15
  tags:
    - always

- name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure PAM variable
    minlen is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*minlen
    line: minlen = {{ var_password_pam_minlen }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.1.1
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_minlen='15'






# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^minlen")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_minlen"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^minlen\\>" "/etc/security/pwquality.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^minlen\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
    if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure PAM password complexity module is enabled in password-auth   [ref]

To enable PAM password complexity in password-auth file: Edit the password section in /etc/pam.d/password-auth to show password requisite pam_pwquality.so.
Rationale:
Enabling PAM password complexity permits to enforce strong passwords and consequently makes the system less prone to dictionary attacks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_pwquality_password_auth
Identifiers and References

References:  CCI-000366, SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - accounts_password_pam_pwquality_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM password complexity module is enabled in password-auth - Check
    if /etc/pam.d/password-auth file is present
  ansible.builtin.stat:
    path: /etc/pam.d/password-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - accounts_password_pam_pwquality_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM password complexity module is enabled in password-auth - Check
    the proper remediation for the system
  block:

  - name: Ensure PAM password complexity module is enabled in password-auth - Define
      the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/password-auth

  - name: Ensure PAM password complexity module is enabled in password-auth - Check
      if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
      authselect custom profile is used if authselect is present
    block:

    - name: Ensure PAM password complexity module is enabled in password-auth - Check
        integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

    - name: Ensure PAM password complexity module is enabled in password-auth - Informative
        message based on the authselect integrity check result
      ansible.builtin.assert:
        that:
        - result_authselect_check_cmd.rc == 0
        fail_msg:
        - authselect integrity check failed. Remediation aborted!
        - This remediation could not be applied because an authselect profile was
          not selected or the selected profile is not intact.
        - It is not recommended to manually edit the PAM files when authselect tool
          is available.
        - In cases where the default authselect profile does not cover a specific
          demand, a custom authselect profile is recommended.
        success_msg:
        - authselect integrity check passed

    - name: Ensure PAM password complexity module is enabled in password-auth - Get
        authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM password complexity module is enabled in password-auth - Define
        the current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Ensure PAM password complexity module is enabled in password-auth - Define
        the new authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

    - name: Ensure PAM password complexity module is enabled in password-auth - Get
        authselect current features to also enable them in the custom profile
      ansible.builtin.shell:
        cmd: authselect current | tail -n+3 | awk '{ print $2 }'
      register: result_authselect_features
      changed_when: false
      when:
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM password complexity module is enabled in password-auth - Check
        if any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM password complexity module is enabled in password-auth - Create
        an authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
        authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
        the authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM password complexity module is enabled in password-auth - Restore
        the authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
        authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM password complexity module is enabled in password-auth - Change
        the PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM password complexity module is enabled in password-auth - Check
      if expected PAM module line is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+requisite\s+pam_pwquality.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

  - name: Ensure PAM password complexity module is enabled in password-auth - Include
      or update the PAM module line in {{ pam_file_path }}
    block:

    - name: Ensure PAM password complexity module is enabled in password-auth - Check
        if required PAM module line is present in {{ pam_file_path }} with different
        control
      ansible.builtin.lineinfile:
        path: '{{ pam_file_path }}'
        regexp: ^\s*password\s+.*\s+pam_pwquality.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
        the correct control for the required PAM module line in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: ^(\s*password\s+).*(\bpam_pwquality.so.*)
        replace: \1requisite \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
        the required PAM module line is included in {{ pam_file_path }}
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        insertafter: ^account.*required.*pam_permit\.so
        line: password    requisite    pam_pwquality.so
      register: result_pam_module_add
      when:
      - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
        > 1

    - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
        authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present is defined
      - result_authselect_present.stat.exists
      - |-
        (result_pam_module_add is defined and result_pam_module_add.changed)
         or (result_pam_module_edit is defined and result_pam_module_edit.changed)
    when:
    - result_pam_line_present.found is defined
    - result_pam_line_present.found == 0

  - name: Ensure PAM password complexity module is enabled in password-auth - Ensure
      authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam__add is defined and result_pam__add.changed)
       or (result_pam__edit is defined and result_pam__edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - accounts_password_pam_pwquality_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

if [ -e "/etc/pam.d/password-auth" ] ; then
    PAM_FILE_PATH="/etc/pam.d/password-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

        CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
        # If not already in use, a custom profile is created preserving the enabled features.
        if [[ ! $CURRENT_PROFILE == custom/* ]]; then
            ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
            authselect create-profile hardening -b $CURRENT_PROFILE
            CURRENT_PROFILE="custom/hardening"
            
            authselect apply-changes -b --backup=before-hardening-custom-profile
            authselect select $CURRENT_PROFILE
            for feature in $ENABLED_FEATURES; do
                authselect enable-feature $feature;
            done
            
            authselect apply-changes -b --backup=after-hardening-custom-profile
        fi
        PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwquality.so\s*.*' "$PAM_FILE_PATH"; then
    # Line matching group + control + module was not found. Check group + module.
    if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwquality.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
        # The control is updated only if one single line matches.
        sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwquality.so.*)/\1'"requisite"' \2/' "$PAM_FILE_PATH"
    else
        LAST_MATCH_LINE=$(grep -nP "^account.*required.*pam_permit\.so" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
        if [ ! -z $LAST_MATCH_LINE ]; then
            sed -i --follow-symlinks $LAST_MATCH_LINE' a password     '"requisite"'    pam_pwquality.so' "$PAM_FILE_PATH"
        else
            echo 'password    '"requisite"'    pam_pwquality.so' >> "$PAM_FILE_PATH"
        fi
    fi
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/password-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure PAM password complexity module is enabled in system-auth   [ref]

To enable PAM password complexity in system-auth file: Edit the password section in /etc/pam.d/system-auth to show password requisite pam_pwquality.so.
Rationale:
Enabling PAM password complexity permits to enforce strong passwords and consequently makes the system less prone to dictionary attacks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_pwquality_system_auth
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - accounts_password_pam_pwquality_system_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM password complexity module is enabled in system-auth - Check if
    /etc/pam.d/system-auth file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - accounts_password_pam_pwquality_system_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM password complexity module is enabled in system-auth - Check the
    proper remediation for the system
  block:

  - name: Ensure PAM password complexity module is enabled in system-auth - Define
      the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Ensure PAM password complexity module is enabled in system-auth - Check
      if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
      authselect custom profile is used if authselect is present
    block:

    - name: Ensure PAM password complexity module is enabled in system-auth - Check
        integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

    - name: Ensure PAM password complexity module is enabled in system-auth - Informative
        message based on the authselect integrity check result
      ansible.builtin.assert:
        that:
        - result_authselect_check_cmd.rc == 0
        fail_msg:
        - authselect integrity check failed. Remediation aborted!
        - This remediation could not be applied because an authselect profile was
          not selected or the selected profile is not intact.
        - It is not recommended to manually edit the PAM files when authselect tool
          is available.
        - In cases where the default authselect profile does not cover a specific
          demand, a custom authselect profile is recommended.
        success_msg:
        - authselect integrity check passed

    - name: Ensure PAM password complexity module is enabled in system-auth - Get
        authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM password complexity module is enabled in system-auth - Define
        the current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Ensure PAM password complexity module is enabled in system-auth - Define
        the new authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

    - name: Ensure PAM password complexity module is enabled in system-auth - Get
        authselect current features to also enable them in the custom profile
      ansible.builtin.shell:
        cmd: authselect current | tail -n+3 | awk '{ print $2 }'
      register: result_authselect_features
      changed_when: false
      when:
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM password complexity module is enabled in system-auth - Check
        if any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM password complexity module is enabled in system-auth - Create
        an authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
        authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
        the authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM password complexity module is enabled in system-auth - Restore
        the authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
        authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM password complexity module is enabled in system-auth - Change
        the PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM password complexity module is enabled in system-auth - Check
      if expected PAM module line is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+requisite\s+pam_pwquality.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

  - name: Ensure PAM password complexity module is enabled in system-auth - Include
      or update the PAM module line in {{ pam_file_path }}
    block:

    - name: Ensure PAM password complexity module is enabled in system-auth - Check
        if required PAM module line is present in {{ pam_file_path }} with different
        control
      ansible.builtin.lineinfile:
        path: '{{ pam_file_path }}'
        regexp: ^\s*password\s+.*\s+pam_pwquality.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
        the correct control for the required PAM module line in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: ^(\s*password\s+).*(\bpam_pwquality.so.*)
        replace: \1requisite \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
        the required PAM module line is included in {{ pam_file_path }}
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        insertafter: ^account.*required.*pam_permit\.so
        line: password    requisite    pam_pwquality.so
      register: result_pam_module_add
      when:
      - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
        > 1

    - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
        authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present is defined
      - result_authselect_present.stat.exists
      - |-
        (result_pam_module_add is defined and result_pam_module_add.changed)
         or (result_pam_module_edit is defined and result_pam_module_edit.changed)
    when:
    - result_pam_line_present.found is defined
    - result_pam_line_present.found == 0

  - name: Ensure PAM password complexity module is enabled in system-auth - Ensure
      authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam__add is defined and result_pam__add.changed)
       or (result_pam__edit is defined and result_pam__edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - accounts_password_pam_pwquality_system_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

if [ -e "/etc/pam.d/system-auth" ] ; then
    PAM_FILE_PATH="/etc/pam.d/system-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

        CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
        # If not already in use, a custom profile is created preserving the enabled features.
        if [[ ! $CURRENT_PROFILE == custom/* ]]; then
            ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
            authselect create-profile hardening -b $CURRENT_PROFILE
            CURRENT_PROFILE="custom/hardening"
            
            authselect apply-changes -b --backup=before-hardening-custom-profile
            authselect select $CURRENT_PROFILE
            for feature in $ENABLED_FEATURES; do
                authselect enable-feature $feature;
            done
            
            authselect apply-changes -b --backup=after-hardening-custom-profile
        fi
        PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwquality.so\s*.*' "$PAM_FILE_PATH"; then
    # Line matching group + control + module was not found. Check group + module.
    if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwquality.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
        # The control is updated only if one single line matches.
        sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwquality.so.*)/\1'"requisite"' \2/' "$PAM_FILE_PATH"
    else
        LAST_MATCH_LINE=$(grep -nP "^account.*required.*pam_permit\.so" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
        if [ ! -z $LAST_MATCH_LINE ]; then
            sed -i --follow-symlinks $LAST_MATCH_LINE' a password     '"requisite"'    pam_pwquality.so' "$PAM_FILE_PATH"
        else
            echo 'password    '"requisite"'    pam_pwquality.so' >> "$PAM_FILE_PATH"
        fi
    fi
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Session   [ref]

To configure the number of retry prompts that are permitted per-session: Edit the pam_pwquality.so statement in /etc/pam.d/system-auth to show retry=3, or a lower value if site policy is more restrictive. The DoD requirement is a maximum of 3 prompts per session.
Rationale:
Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks. Note that this is different from account lockout, which is provided by the pam_faillock module.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_retry
Identifiers and References

References:  1, 11, 12, 15, 16, 3, 5, 9, 5.5.3, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, PR.IP-1, FMT_MOF_EXT.1, SRG-OS-000069-GPOS-00037, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.3
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - accounts_password_pam_retry
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_password_pam_retry # promote to variable
  set_fact:
    var_password_pam_retry: !!str 3
  tags:
    - always

- name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
    Per-Session - Check if expected PAM module line is present in /etc/pam.d/system-auth
  ansible.builtin.lineinfile:
    path: /etc/pam.d/system-auth
    regexp: ^\s*password\s+requisite\s+pam_pwquality.so\s*.*
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_line_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.5.3
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - accounts_password_pam_retry
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
    Per-Session - Include or update the PAM module line in /etc/pam.d/system-auth
  block:

  - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
      Permitted Per-Session - Check if required PAM module line is present in /etc/pam.d/system-auth
      with different control
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: ^\s*password\s+.*\s+pam_pwquality.so\s*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_other_control_present

  - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
      Permitted Per-Session - Ensure the correct control for the required PAM module
      line in /etc/pam.d/system-auth
    ansible.builtin.replace:
      dest: /etc/pam.d/system-auth
      regexp: ^(\s*password\s+).*(\bpam_pwquality.so.*)
      replace: \1requisite \2
    register: result_pam_module_edit
    when:
    - result_pam_line_other_control_present.found == 1

  - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
      Permitted Per-Session - Ensure the required PAM module line is included in /etc/pam.d/system-auth
    ansible.builtin.lineinfile:
      dest: /etc/pam.d/system-auth
      insertafter: ^\s*account
      line: password    requisite    pam_pwquality.so
    register: result_pam_module_add
    when:
    - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
      > 1

  - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
      Permitted Per-Session - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present is defined
    - result_authselect_present.stat.exists
    - |-
      (result_pam_module_add is defined and result_pam_module_add.changed)
       or (result_pam_module_edit is defined and result_pam_module_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_line_present.found is defined
  - result_pam_line_present.found == 0
  tags:
  - CJIS-5.5.3
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - accounts_password_pam_retry
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
    Per-Session - Check if the required PAM module option is present in /etc/pam.d/system-auth
  ansible.builtin.lineinfile:
    path: /etc/pam.d/system-auth
    regexp: ^\s*password\s+requisite\s+pam_pwquality.so\s*.*\sretry\b
    state: absent
  check_mode: true
  changed_when: false
  register: result_pam_module_retry_option_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.5.3
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - accounts_password_pam_retry
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
    Per-Session - Ensure the "retry" PAM option for "pam_pwquality.so" is included
    in /etc/pam.d/system-auth
  ansible.builtin.lineinfile:
    path: /etc/pam.d/system-auth
    backrefs: true
    regexp: ^(\s*password\s+requisite\s+pam_pwquality.so.*)
    line: \1 retry={{ var_password_pam_retry }}
    state: present
  register: result_pam_retry_add
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_retry_option_present.found == 0
  tags:
  - CJIS-5.5.3
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - accounts_password_pam_retry
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
    Per-Session - Ensure the required value for "retry" PAM option from "pam_pwquality.so"
    in /etc/pam.d/system-auth
  ansible.builtin.lineinfile:
    path: /etc/pam.d/system-auth
    backrefs: true
    regexp: ^(\s*password\s+requisite\s+pam_pwquality.so\s+.*)(retry)=[0-9a-zA-Z]+\s*(.*)
    line: \1\2={{ var_password_pam_retry }} \3
  register: result_pam_retry_edit
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_module_retry_option_present.found > 0
  tags:
  - CJIS-5.5.3
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(4)
  - accounts_password_pam_retry
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

var_password_pam_retry='3'



	
		if [ -e "/etc/pam.d/system-auth" ] ; then
    PAM_FILE_PATH="/etc/pam.d/system-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

        CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
        # If not already in use, a custom profile is created preserving the enabled features.
        if [[ ! $CURRENT_PROFILE == custom/* ]]; then
            ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
            authselect create-profile hardening -b $CURRENT_PROFILE
            CURRENT_PROFILE="custom/hardening"
            
            authselect apply-changes -b --backup=before-hardening-custom-profile
            authselect select $CURRENT_PROFILE
            for feature in $ENABLED_FEATURES; do
                authselect enable-feature $feature;
            done
            
            authselect apply-changes -b --backup=after-hardening-custom-profile
        fi
        PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwquality.so\s*.*' "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwquality.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwquality.so.*)/\1'"requisite"' \2/' "$PAM_FILE_PATH"
            else
                LAST_MATCH_LINE=$(grep -nP "^\s*account" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
                if [ ! -z $LAST_MATCH_LINE ]; then
                    sed -i --follow-symlinks $LAST_MATCH_LINE' a password     '"requisite"'    pam_pwquality.so' "$PAM_FILE_PATH"
                else
                    echo 'password    '"requisite"'    pam_pwquality.so' >> "$PAM_FILE_PATH"
                fi
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwquality.so\s*.*\sretry\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"requisite"'\s+pam_pwquality.so.*/ s/$/ retry='"$var_password_pam_retry"'/' "$PAM_FILE_PATH"
        else
            sed -i -E --follow-symlinks 's/(\s*password\s+'"requisite"'\s+pam_pwquality.so\s+.*)('"retry"'=)[[:alnum:]]+\s*(.*)/\1\2'"$var_password_pam_retry"' \3/' "$PAM_FILE_PATH"
        fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Set Password Hashing Algorithm   Group contains 3 rules
[ref]   The system's default algorithm for storing password hashes in /etc/shadow is SHA-512. This can be configured in several locations.

Rule   Set Password Hashing Algorithm in /etc/login.defs   [ref]

In /etc/login.defs, add or correct the following line to ensure the system will use SHA512 as the hashing algorithm:
ENCRYPT_METHOD SHA512
Rationale:
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text.

Using a stronger hashing algorithm makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_logindefs
Identifiers and References

References:  BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2, SRG-OS-000073-GPOS-00041


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_logindefs
- name: XCCDF Value var_password_hashing_algorithm # promote to variable
  set_fact:
    var_password_hashing_algorithm: !!str SHA512
  tags:
    - always

- name: Set Password Hashing Algorithm in /etc/login.defs
  lineinfile:
    dest: /etc/login.defs
    regexp: ^#?ENCRYPT_METHOD
    line: ENCRYPT_METHOD {{ var_password_hashing_algorithm }}
    state: present
    create: true
  when: '"shadow-utils" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - set_password_hashing_algorithm_logindefs

# Remediation is applicable only in certain platforms
if rpm --quiet -q shadow-utils; then

var_password_hashing_algorithm='SHA512'


if grep --silent ^ENCRYPT_METHOD /etc/login.defs ; then
	sed -i "s/^ENCRYPT_METHOD .*/ENCRYPT_METHOD $var_password_hashing_algorithm/g" /etc/login.defs
else
	echo "" >> /etc/login.defs
	echo "ENCRYPT_METHOD $var_password_hashing_algorithm" >> /etc/login.defs
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set PAM''s Password Hashing Algorithm - password-auth   [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In /etc/pam.d/password-auth, the password section of the file controls which PAM modules execute during a password change. Set the pam_unix.so module in the password section to include the argument sha512, as shown below:
password    sufficient    pam_unix.so sha512 other arguments...

This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default.
Rationale:
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text.

This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the crypt_style configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_passwordauth
Identifiers and References

References:  BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, CCI-000803, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_passwordauth

- name: Set PAM's Password Hashing Algorithm - password-auth - Check if /etc/pam.d/password-auth
    file is present
  ansible.builtin.stat:
    path: /etc/pam.d/password-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_passwordauth

- name: Set PAM's Password Hashing Algorithm - password-auth - Check the proper remediation
    for the system
  block:

  - name: Set PAM's Password Hashing Algorithm - password-auth - Define the PAM file
      to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/password-auth

  - name: Set PAM's Password Hashing Algorithm - password-auth - Check if system relies
      on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
      custom profile is used if authselect is present
    block:

    - name: Set PAM's Password Hashing Algorithm - password-auth - Check integrity
        of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

    - name: Set PAM's Password Hashing Algorithm - password-auth - Informative message
        based on the authselect integrity check result
      ansible.builtin.assert:
        that:
        - result_authselect_check_cmd.rc == 0
        fail_msg:
        - authselect integrity check failed. Remediation aborted!
        - This remediation could not be applied because an authselect profile was
          not selected or the selected profile is not intact.
        - It is not recommended to manually edit the PAM files when authselect tool
          is available.
        - In cases where the default authselect profile does not cover a specific
          demand, a custom authselect profile is recommended.
        success_msg:
        - authselect integrity check passed

    - name: Set PAM's Password Hashing Algorithm - password-auth - Get authselect
        current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Set PAM's Password Hashing Algorithm - password-auth - Define the current
        authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Set PAM's Password Hashing Algorithm - password-auth - Define the new
        authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - password-auth - Get authselect
        current features to also enable them in the custom profile
      ansible.builtin.shell:
        cmd: authselect current | tail -n+3 | awk '{ print $2 }'
      register: result_authselect_features
      changed_when: false
      when:
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - password-auth - Check if any custom
        profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - password-auth - Create an authselect
        custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the authselect
        custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Set PAM's Password Hashing Algorithm - password-auth - Restore the authselect
        features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Set PAM's Password Hashing Algorithm - password-auth - Change the PAM
        file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Set PAM's Password Hashing Algorithm - password-auth - Check if expected
      PAM module line is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+sufficient\s+pam_unix.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

  - name: Set PAM's Password Hashing Algorithm - password-auth - Include or update
      the PAM module line in {{ pam_file_path }}
    block:

    - name: Set PAM's Password Hashing Algorithm - password-auth - Check if required
        PAM module line is present in {{ pam_file_path }} with different control
      ansible.builtin.lineinfile:
        path: '{{ pam_file_path }}'
        regexp: ^\s*password\s+.*\s+pam_unix.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the correct
        control for the required PAM module line in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
        replace: \1sufficient \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the required
        PAM module line is included in {{ pam_file_path }}
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        line: password    sufficient    pam_unix.so
      register: result_pam_module_add
      when:
      - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
        > 1

    - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present is defined
      - result_authselect_present.stat.exists
      - |-
        (result_pam_module_add is defined and result_pam_module_add.changed)
         or (result_pam_module_edit is defined and result_pam_module_edit.changed)
    when:
    - result_pam_line_present.found is defined
    - result_pam_line_present.found == 0

  - name: Set PAM's Password Hashing Algorithm - password-auth - Check if the required
      PAM module option is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+sufficient\s+pam_unix.so\s*.*\ssha512\b
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_module_sha512_option_present

  - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure the "sha512"
      PAM option for "pam_unix.so" is included in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+sufficient\s+pam_unix.so.*)
      line: \1 sha512
      state: present
    register: result_pam_sha512_add
    when:
    - result_pam_module_sha512_option_present.found == 0

  - name: Set PAM's Password Hashing Algorithm - password-auth - Ensure authselect
      changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam_sha512_add is defined and result_pam_sha512_add.changed)
       or (result_pam_sha512_edit is defined and result_pam_sha512_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_passwordauth

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

if [ -e "/etc/pam.d/password-auth" ] ; then
    PAM_FILE_PATH="/etc/pam.d/password-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

        CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
        # If not already in use, a custom profile is created preserving the enabled features.
        if [[ ! $CURRENT_PROFILE == custom/* ]]; then
            ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
            authselect create-profile hardening -b $CURRENT_PROFILE
            CURRENT_PROFILE="custom/hardening"
            
            authselect apply-changes -b --backup=before-hardening-custom-profile
            authselect select $CURRENT_PROFILE
            for feature in $ENABLED_FEATURES; do
                authselect enable-feature $feature;
            done
            
            authselect apply-changes -b --backup=after-hardening-custom-profile
        fi
        PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
            else
                echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\ssha512\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ sha512/' "$PAM_FILE_PATH"
        fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/password-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set PAM''s Password Hashing Algorithm   [ref]

The PAM system service can be configured to only store encrypted representations of passwords. In "/etc/pam.d/system-auth", the password section of the file controls which PAM modules execute during a password change. Set the pam_unix.so module in the password section to include the argument sha512, as shown below:
password    sufficient    pam_unix.so sha512 other arguments...

This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default.
Rationale:
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text.

This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the crypt_style configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_systemauth
Identifiers and References

References:  BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, CCI-000803, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

- name: Set PAM's Password Hashing Algorithm - Check if /etc/pam.d/system-auth file
    is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

- name: Set PAM's Password Hashing Algorithm - Check the proper remediation for the
    system
  block:

  - name: Set PAM's Password Hashing Algorithm - Define the PAM file to be edited
      as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Set PAM's Password Hashing Algorithm - Check if system relies on authselect
      tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Set PAM's Password Hashing Algorithm - Ensure authselect custom profile
      is used if authselect is present
    block:

    - name: Set PAM's Password Hashing Algorithm - Check integrity of authselect current
        profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

    - name: Set PAM's Password Hashing Algorithm - Informative message based on the
        authselect integrity check result
      ansible.builtin.assert:
        that:
        - result_authselect_check_cmd.rc == 0
        fail_msg:
        - authselect integrity check failed. Remediation aborted!
        - This remediation could not be applied because an authselect profile was
          not selected or the selected profile is not intact.
        - It is not recommended to manually edit the PAM files when authselect tool
          is available.
        - In cases where the default authselect profile does not cover a specific
          demand, a custom authselect profile is recommended.
        success_msg:
        - authselect integrity check passed

    - name: Set PAM's Password Hashing Algorithm - Get authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Set PAM's Password Hashing Algorithm - Define the current authselect profile
        as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Define the new authselect custom
        profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Get authselect current features
        to also enable them in the custom profile
      ansible.builtin.shell:
        cmd: authselect current | tail -n+3 | awk '{ print $2 }'
      register: result_authselect_features
      changed_when: false
      when:
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Check if any custom profile with
        the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
        based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Set PAM's Password Hashing Algorithm - Ensure the authselect custom profile
        is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Set PAM's Password Hashing Algorithm - Restore the authselect features
        in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Set PAM's Password Hashing Algorithm - Change the PAM file to be edited
        according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Set PAM's Password Hashing Algorithm - Check if expected PAM module line
      is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+sufficient\s+pam_unix.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

  - name: Set PAM's Password Hashing Algorithm - Include or update the PAM module
      line in {{ pam_file_path }}
    block:

    - name: Set PAM's Password Hashing Algorithm - Check if required PAM module line
        is present in {{ pam_file_path }} with different control
      ansible.builtin.lineinfile:
        path: '{{ pam_file_path }}'
        regexp: ^\s*password\s+.*\s+pam_unix.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: Set PAM's Password Hashing Algorithm - Ensure the correct control for
        the required PAM module line in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
        replace: \1sufficient \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: Set PAM's Password Hashing Algorithm - Ensure the required PAM module
        line is included in {{ pam_file_path }}
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        line: password    sufficient    pam_unix.so
      register: result_pam_module_add
      when:
      - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
        > 1

    - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present is defined
      - result_authselect_present.stat.exists
      - |-
        (result_pam_module_add is defined and result_pam_module_add.changed)
         or (result_pam_module_edit is defined and result_pam_module_edit.changed)
    when:
    - result_pam_line_present.found is defined
    - result_pam_line_present.found == 0

  - name: Set PAM's Password Hashing Algorithm - Check if the required PAM module
      option is present in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+sufficient\s+pam_unix.so\s*.*\ssha512\b
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_module_sha512_option_present

  - name: Set PAM's Password Hashing Algorithm - Ensure the "sha512" PAM option for
      "pam_unix.so" is included in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+sufficient\s+pam_unix.so.*)
      line: \1 sha512
      state: present
    register: result_pam_sha512_add
    when:
    - result_pam_module_sha512_option_present.found == 0

  - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam_sha512_add is defined and result_pam_sha512_add.changed)
       or (result_pam_sha512_edit is defined and result_pam_sha512_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - CJIS-5.6.2.2
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

if [ -e "/etc/pam.d/system-auth" ] ; then
    PAM_FILE_PATH="/etc/pam.d/system-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

        CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
        # If not already in use, a custom profile is created preserving the enabled features.
        if [[ ! $CURRENT_PROFILE == custom/* ]]; then
            ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
            authselect create-profile hardening -b $CURRENT_PROFILE
            CURRENT_PROFILE="custom/hardening"
            
            authselect apply-changes -b --backup=before-hardening-custom-profile
            authselect select $CURRENT_PROFILE
            for feature in $ENABLED_FEATURES; do
                authselect enable-feature $feature;
            done
            
            authselect apply-changes -b --backup=after-hardening-custom-profile
        fi
        PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
            else
                echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\ssha512\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ sha512/' "$PAM_FILE_PATH"
        fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Protect Accounts by Restricting Password-Based Login   Group contains 3 groups and 10 rules
[ref]   Conventionally, Unix shell accounts are accessed by providing a username and password to a login program, which tests these values for correctness using the /etc/passwd and /etc/shadow files. Password-based login is vulnerable to guessing of weak passwords, and to sniffing and man-in-the-middle attacks against passwords entered over a network or at an insecure console. Therefore, mechanisms for accessing accounts by entering usernames and passwords should be restricted to those which are operationally necessary.
Group   Set Account Expiration Parameters   Group contains 1 rule
Group   Verify Proper Storage and Existence of Password Hashes   Group contains 3 rules
[ref]   By default, password hashes for local accounts are stored in the second field (colon-separated) in /etc/shadow. This file should be readable only by processes running with root credentials, preventing users from casually accessing others' password hashes and attempting to crack them. However, it remains possible to misconfigure the system and store password hashes in world-readable files such as /etc/passwd, or to even store passwords themselves in plaintext on the system. Using system-provided tools for password change/creation should allow administrators to avoid such misconfiguration.

Rule   All GIDs referenced in /etc/passwd must be defined in /etc/group   [ref]

Add a group to the system for each GID referenced without a corresponding group.
Rationale:
If a user is assigned the Group Identifier (GID) of a group not existing on the system, and a group with the Group Identifier (GID) is subsequently created, the user may have unintended rights to any files associated with the group.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_gid_passwd_group_same
Identifiers and References

References:  1, 12, 15, 16, 5, 5.5.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000764, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.5.a, 8.2.2, SRG-OS-000104-GPOS-00051

Rule   Prevent Login to Accounts With Empty Password   [ref]

If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the nullok in /etc/pam.d/system-auth and /etc/pam.d/password-auth to prevent logins with empty passwords.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.
Rationale:
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_no_empty_passwords
Identifiers and References

References:  1, 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, CCI-000366, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(1)(a), IA-5(c), CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, FIA_UAU.1, Req-8.2.3, 8.3.6, 8.3.9, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,%23%20Generated%20by%20authselect%20on%20Sat%20Oct%2027%2014%3A59%3A36%202018%0A%23%20Do%20not%20modify%20this%20file%20manually.%0A%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_env.so%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_faildelay.so%20delay%3D2000000%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_fprintd.so%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20try_first_pass%0Aauth%20%20%20%20%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet_success%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20forward_pass%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3C%201000%20quiet%0Aaccount%20%20%20%20%20%5Bdefault%3Dbad%20success%3Dok%20user_unknown%3Dignore%5D%20pam_sss.so%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_permit.so%0A%0Apassword%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_pwquality.so%20try_first_pass%20local_users_only%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20sha512%20shadow%20try_first_pass%20use_authtok%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20use_authtok%0Apassword%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_keyinit.so%20revoke%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_limits.so%0A-session%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_systemd.so%0Asession%20%20%20%20%20%5Bsuccess%3D1%20default%3Dignore%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20service%20in%20crond%20quiet%20use_uid%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%0A
        mode: 0644
        path: /etc/pam.d/password-auth
        overwrite: true
      - contents:
          source: data:,%23%20Generated%20by%20authselect%20on%20Sat%20Oct%2027%2014%3A59%3A36%202018%0A%23%20Do%20not%20modify%20this%20file%20manually.%0A%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_env.so%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_faildelay.so%20delay%3D2000000%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_fprintd.so%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet%0Aauth%20%20%20%20%20%20%20%20%5Bdefault%3D1%20ignore%3Dignore%20success%3Dok%5D%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20try_first_pass%0Aauth%20%20%20%20%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3E%3D%201000%20quiet_success%0Aauth%20%20%20%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20forward_pass%0Aauth%20%20%20%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_localuser.so%0Aaccount%20%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20uid%20%3C%201000%20quiet%0Aaccount%20%20%20%20%20%5Bdefault%3Dbad%20success%3Dok%20user_unknown%3Dignore%5D%20pam_sss.so%0Aaccount%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_permit.so%0A%0Apassword%20%20%20%20requisite%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_pwquality.so%20try_first_pass%20local_users_only%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%20sha512%20shadow%20try_first_pass%20use_authtok%0Apassword%20%20%20%20sufficient%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%20use_authtok%0Apassword%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_deny.so%0A%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_keyinit.so%20revoke%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_limits.so%0A-session%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_systemd.so%0Asession%20%20%20%20%20%5Bsuccess%3D1%20default%3Dignore%5D%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_succeed_if.so%20service%20in%20crond%20quiet%20use_uid%0Asession%20%20%20%20%20required%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_unix.so%0Asession%20%20%20%20%20optional%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20pam_sss.so%0A
        mode: 0644
        path: /etc/pam.d/system-auth
        overwrite: true

Complexity:low
Disruption:medium
Strategy:configure
- name: Prevent Login to Accounts With Empty Password - Check if system relies on
    authselect
  ansible.builtin.stat:
    path: /usr/bin/authselect
  register: result_authselect_present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - configure_strategy
  - high_severity
  - low_complexity
  - medium_disruption
  - no_empty_passwords
  - no_reboot_needed

- name: Prevent Login to Accounts With Empty Password - Remediate using authselect
  block:

  - name: Prevent Login to Accounts With Empty Password - Check integrity of authselect
      current profile
    ansible.builtin.command:
      cmd: authselect check
    register: result_authselect_check_cmd
    changed_when: false
    failed_when: false

  - name: Prevent Login to Accounts With Empty Password - Informative message based
      on the authselect integrity check result
    ansible.builtin.assert:
      that:
      - result_authselect_check_cmd.rc == 0
      fail_msg:
      - authselect integrity check failed. Remediation aborted!
      - This remediation could not be applied because an authselect profile was not
        selected or the selected profile is not intact.
      - It is not recommended to manually edit the PAM files when authselect tool
        is available.
      - In cases where the default authselect profile does not cover a specific demand,
        a custom authselect profile is recommended.
      success_msg:
      - authselect integrity check passed

  - name: Prevent Login to Accounts With Empty Password - Get authselect current features
    ansible.builtin.shell:
      cmd: authselect current | tail -n+3 | awk '{ print $2 }'
    register: result_authselect_features
    changed_when: false
    when:
    - result_authselect_check_cmd is success

  - name: Prevent Login to Accounts With Empty Password - Ensure "without-nullok"
      feature is enabled using authselect tool
    ansible.builtin.command:
      cmd: authselect enable-feature without-nullok
    register: result_authselect_enable_feature_cmd
    when:
    - result_authselect_check_cmd is success
    - result_authselect_features.stdout is not search("without-nullok")

  - name: Prevent Login to Accounts With Empty Password - Ensure authselect changes
      are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_enable_feature_cmd is not skipped
    - result_authselect_enable_feature_cmd is success
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - result_authselect_present.stat.exists
  tags:
  - CJIS-5.5.2
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - configure_strategy
  - high_severity
  - low_complexity
  - medium_disruption
  - no_empty_passwords
  - no_reboot_needed

- name: Prevent Login to Accounts With Empty Password - Remediate directly editing
    PAM files
  ansible.builtin.replace:
    dest: '{{ item }}'
    regexp: nullok
  loop:
  - /etc/pam.d/system-auth
  - /etc/pam.d/password-auth
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not result_authselect_present.stat.exists
  tags:
  - CJIS-5.5.2
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - configure_strategy
  - high_severity
  - low_complexity
  - medium_disruption
  - no_empty_passwords
  - no_reboot_needed

Complexity:low
Disruption:medium
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -f /usr/bin/authselect ]; then
    if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
authselect enable-feature without-nullok

authselect apply-changes -b
else
    
if grep -qP '^\s*auth\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/system-auth"; then
    sed -i -E --follow-symlinks 's/(.*auth.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/system-auth"
fi
    
if grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/system-auth"; then
    sed -i -E --follow-symlinks 's/(.*password.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/system-auth"
fi
    
if grep -qP '^\s*auth\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/password-auth"; then
    sed -i -E --follow-symlinks 's/(.*auth.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/password-auth"
fi
    
if grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s.*\bnullok\b' "/etc/pam.d/password-auth"; then
    sed -i -E --follow-symlinks 's/(.*password.*'"sufficient"'.*pam_unix.so.*)\snullok=?[[:alnum:]]*(.*)/\1\2/g' "/etc/pam.d/password-auth"
fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure There Are No Accounts With Blank or Null Passwords   [ref]

Check the "/etc/shadow" file for blank passwords with the following command:
$ sudo awk -F: '!$2 {print $1}' /etc/shadow
If the command returns any results, this is a finding. Configure all accounts on the system to have a password or lock the account with the following commands: Perform a password reset:
$ sudo passwd [username]
Lock an account:
$ sudo passwd -l [username]
Warning:  Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.
Rationale:
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_no_empty_passwords_etc_shadow
Identifiers and References

References:  CCI-000366, CM-6(b), CM-6.1(iv), SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Collect users with no password
  command: |
    awk -F: '!$2 {print $1}' /etc/shadow
  register: users_nopasswd
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - high_severity
  - low_complexity
  - low_disruption
  - no_empty_passwords_etc_shadow
  - no_reboot_needed
  - restrict_strategy

- name: Lock users with no password
  command: |
    passwd -l {{ item }}
  with_items: '{{ users_nopasswd.stdout_lines }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - users_nopasswd.stdout_lines | length > 0
  tags:
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - high_severity
  - low_complexity
  - low_disruption
  - no_empty_passwords_etc_shadow
  - no_reboot_needed
  - restrict_strategy
Group   Restrict Root Logins   Group contains 3 rules
[ref]   Direct root logins should be allowed only for emergency use. In normal situations, the administrator should access the system via a unique unprivileged account, and then use su or sudo to execute privileged commands. Discouraging administrators from accessing the root account directly ensures an audit trail in organizations with multiple administrators. Locking down the channels through which root can connect directly also reduces opportunities for password-guessing against the root account. The login program uses the file /etc/securetty to determine which interfaces should allow root logins. The virtual devices /dev/console and /dev/tty* represent the system consoles (accessible via the Ctrl-Alt-F1 through Ctrl-Alt-F6 keyboard sequences on a default installation). The default securetty file also contains /dev/vc/*. These are likely to be deprecated in most environments, but may be retained for compatibility. Root should also be prohibited from connecting via network protocols. Other sections of this document include guidance describing how to prevent root from logging in via SSH.

Rule   Verify Only Root Has UID 0   [ref]

If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed.
If the account is associated with system commands or applications the UID should be changed to one greater than "0" but less than "1000." Otherwise assign a UID greater than "1000" that has not already been assigned.
Rationale:
An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero
Identifiers and References

References:  1, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, AC-6(5), IA-4(b), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, Req-8.5, 8.2.2, 8.2.3, SRG-OS-000480-GPOS-00227


awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs --no-run-if-empty --max-lines=1 passwd -l

Rule   Verify Root Has A Primary GID 0   [ref]

The root user should have a primary group of 0.
Rationale:
To help ensure that root-owned files are not inadvertently exposed to other users.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_accounts_root_gid_zero
Identifiers and References

References:  Req-8.1.1, 8.2.1

Rule   Enforce usage of pam_wheel for su authentication   [ref]

To ensure that only users who are members of the wheel group can run commands with altered privileges through the su command, make sure that the following line exists in the file /etc/pam.d/su:
auth required pam_wheel.so use_uid
Warning:  Members of "wheel" or GID 0 groups are checked by default if the group option is not set for pam_wheel.so module. Therefore, members of these groups should be manually checked or a different group should be informed according to the site policy.
Rationale:
The su program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such command is considered a good security practice.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_use_pam_wheel_for_su
Identifiers and References

References:  FMT_SMF_EXT.1.1, 8.6.1, SRG-OS-000373-GPOS-00156, SRG-OS-000312-GPOS-00123


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - PCI-DSSv4-8.6.1
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - use_pam_wheel_for_su

- name: Restrict usage of su command only to members of wheel group
  replace:
    path: /etc/pam.d/su
    regexp: ^[\s]*#[\s]*auth[\s]+required[\s]+pam_wheel\.so[\s]+use_uid$
    replace: auth             required        pam_wheel.so use_uid
  when: '"pam" in ansible_facts.packages'
  tags:
  - PCI-DSSv4-8.6.1
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - use_pam_wheel_for_su

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then

# uncomment the option if commented
  sed '/^[[:space:]]*#[[:space:]]*auth[[:space:]]\+required[[:space:]]\+pam_wheel\.so[[:space:]]\+use_uid$/s/^[[:space:]]*#//' -i /etc/pam.d/su

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure All Groups on the System Have Unique Group ID   [ref]

Change the group name or delete groups, so each has a unique id.
Warning:  Automatic remediation of this control is not available due to the unique requirements of each system.
Rationale:
To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_group_unique_id
Identifiers and References

References:  CCI-000764, 8.2.1, SRG-OS-000104-GPOS-00051

Rule   Ensure All Groups on the System Have Unique Group Names   [ref]

Change the group name or delete groups, so each has a unique name.
Warning:  Automatic remediation of this control is not available due to the unique requirements of each system.
Rationale:
To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_group_unique_name
Identifiers and References

References:  8.2.1

Group   Secure Session Configuration Files for Login Accounts   Group contains 2 groups and 10 rules
[ref]   When a user logs into a Unix account, the system configures the user's session by reading a number of files. Many of these files are located in the user's home directory, and may have weak permissions as a result of user error or misconfiguration. If an attacker can modify or even read certain types of account configuration information, they can often gain full access to the affected user's account. Therefore, it is important to test and correct configuration file permissions for interactive accounts, particularly those of privileged users such as root or system administrators.
Group   Ensure that No Dangerous Directories Exist in Root's Path   Group contains 1 rule
[ref]   The active path of the root account can be obtained by starting a new root shell and running:
# echo $PATH
This will produce a colon-separated list of directories in the path.

Certain path elements could be considered dangerous, as they could lead to root executing unknown or untrusted programs, which could contain malicious code. Since root may sometimes work inside untrusted directories, the . character, which represents the current directory, should never be in the root path, nor should any directory which can be written to by an unprivileged or semi-privileged (system) user.

It is a good practice for administrators to always execute privileged commands by typing the full path to the command.

Rule   Ensure that Root's Path Does Not Include World or Group-Writable Directories   [ref]

For each element in root's path, run:
# ls -ld DIR
and ensure that write permissions are disabled for group and other.
Rationale:
Such entries increase the risk that root could execute code provided by unprivileged users, and potentially malicious code.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_root_path_dirs_no_write
Identifiers and References

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, CCI-000366, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-6(a), CM-6(a), PR.IP-1


Complexity:low
Disruption:medium
Strategy:restrict
- name: Get root paths which are not symbolic links
  stat:
    path: '{{ item }}'
  changed_when: false
  failed_when: false
  register: root_paths
  with_items: '{{ ansible_env.PATH.split('':'') }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(a)
  - accounts_root_path_dirs_no_write
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Disable writability to root directories
  file:
    path: '{{ item.item }}'
    mode: g-w,o-w
  with_items: '{{ root_paths.results }}'
  when:
  - root_paths.results is defined
  - item.stat.exists
  - not item.stat.islnk
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(a)
  - accounts_root_path_dirs_no_write
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
Group   Ensure that Users Have Sensible Umask Values   Group contains 3 rules
[ref]   The umask setting controls the default permissions for the creation of new files. With a default umask setting of 077, files and directories created by users will not be readable by any other user on the system. Users who wish to make specific files group- or world-readable can accomplish this by using the chmod command. Additionally, users can make all their files readable to their group by default by setting a umask of 027 in their shell configuration files. If default per-user groups exist (that is, if every user has a default group whose name is the same as that user's username and whose only member is the user), then it may even be safe for users to select a umask of 007, making it very easy to intentionally share files with groups of which the user is a member.

Rule   Ensure the Default Bash Umask is Set Correctly   [ref]

To ensure the default umask for users of the Bash shell is set properly, add or correct the umask setting in /etc/bashrc to read as follows:
umask 027
Rationale:
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_umask_etc_bashrc
Identifiers and References

References:  BP28(R35), 18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-2, 8.6.1, SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_user_umask # promote to variable
  set_fact:
    var_accounts_user_umask: !!str 027
  tags:
    - always

- name: Check if umask in /etc/bashrc is already set
  ansible.builtin.lineinfile:
    path: /etc/bashrc
    regexp: ^(\s*)umask\s+.*
    state: absent
  check_mode: true
  changed_when: false
  register: umask_replace
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_bashrc
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Replace user umask in /etc/bashrc
  ansible.builtin.replace:
    path: /etc/bashrc
    regexp: ^(\s*)umask(\s+).*
    replace: \g<1>umask\g<2>{{ var_accounts_user_umask }}
  when: umask_replace.found > 0
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_bashrc
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default umask is Appended Correctly
  ansible.builtin.lineinfile:
    create: true
    path: /etc/bashrc
    line: umask {{ var_accounts_user_umask }}
  when: umask_replace.found == 0
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_bashrc
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


var_accounts_user_umask='027'






grep -q "^\s*umask" /etc/bashrc && \
  sed -i -E -e "s/^(\s*umask).*/\1 $var_accounts_user_umask/g" /etc/bashrc
if ! [ $? -eq 0 ]; then
    echo "umask $var_accounts_user_umask" >> /etc/bashrc
fi

Rule   Ensure the Default Umask is Set Correctly in /etc/profile   [ref]

To ensure the default umask controlled by /etc/profile is set properly, add or correct the umask setting in /etc/profile to read as follows:
umask 027
Note that /etc/profile also reads scrips within /etc/profile.d directory. These scripts are also valid files to set umask value. Therefore, they should also be considered during the check and properly remediated, if necessary.
Rationale:
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_umask_etc_profile
Identifiers and References

References:  BP28(R35), 18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-2, 8.6.1, SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_user_umask # promote to variable
  set_fact:
    var_accounts_user_umask: !!str 027
  tags:
    - always

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Locate Profile
    Configuration Files Where umask Is Defined
  ansible.builtin.find:
    paths:
    - /etc/profile.d
    patterns:
    - sh.local
    - '*.sh'
    contains: ^[\s]*umask\s+\d+
  register: result_profile_d_files
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Replace Existing
    umask Value in Files From /etc/profile.d
  ansible.builtin.replace:
    path: '{{ item.path }}'
    regexp: ^(\s*)umask\s+\d+
    replace: \1umask {{ var_accounts_user_umask }}
  loop: '{{ result_profile_d_files.files }}'
  register: result_umask_replaced_profile_d
  when: result_profile_d_files.matched
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Is
    Set in /etc/profile if Not Already Set Elsewhere
  ansible.builtin.lineinfile:
    create: true
    mode: 420
    path: /etc/profile
    line: umask {{ var_accounts_user_umask }}
  when: not result_profile_d_files.matched
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Value
    For All Existing umask Definition in /etc/profile
  ansible.builtin.replace:
    path: /etc/profile
    regexp: ^(\s*)umask\s+\d+
    replace: \1umask {{ var_accounts_user_umask }}
  register: result_umask_replaced_profile
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-8.6.1
  - accounts_umask_etc_profile
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict

var_accounts_user_umask='027'


readarray -t profile_files < <(find /etc/profile.d/ -type f -name '*.sh' -or -name 'sh.local')

for file in "${profile_files[@]}" /etc/profile; do
  grep -qE '^[^#]*umask' "$file" && sed -i "s/umask.*/umask $var_accounts_user_umask/g" "$file"
done

if ! grep -qrE '^[^#]*umask' /etc/profile*; then
  echo "umask $var_accounts_user_umask" >> /etc/profile
fi

Rule   Set Interactive Session Timeout   [ref]

Setting the TMOUT option in /etc/profile ensures that all user sessions will terminate based on inactivity. The value of TMOUT should be exported and read only. The TMOUT setting in a file loaded by /etc/profile, e.g. /etc/profile.d/tmout.sh should read as follows:
declare -xr TMOUT=900
Rationale:
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_tmout
Identifiers and References

References:  BP28(R29), 1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.11, CCI-000057, CCI-001133, CCI-002361, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-12, SC-10, AC-2(5), CM-6(a), PR.AC-7, FMT_MOF_EXT.1, 8.6.1, SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_tmout # promote to variable
  set_fact:
    var_accounts_tmout: !!str 900
  tags:
    - always

- name: Correct any occurrence of TMOUT in /etc/profile
  replace:
    path: /etc/profile
    regexp: ^[^#].*TMOUT=.*
    replace: declare -xr TMOUT={{ var_accounts_tmout }}
  register: profile_replaced
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Interactive Session Timeout
  lineinfile:
    path: /etc/profile.d/tmout.sh
    create: true
    regexp: TMOUT=
    line: declare -xr TMOUT={{ var_accounts_tmout }}
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_accounts_tmout='900'


# if 0, no occurence of tmout found, if 1, occurence found
tmout_found=0


for f in /etc/profile /etc/profile.d/*.sh; do

    if grep --silent '^[^#].*TMOUT' $f; then
        sed -i -E "s/^(.*)TMOUT\s*=\s*(\w|\$)*(.*)$/declare -xr TMOUT=$var_accounts_tmout\3/g" $f
        tmout_found=1
    fi
done

if [ $tmout_found -eq 0 ]; then
        echo -e "\n# Set TMOUT to $var_accounts_tmout per security requirements" >> /etc/profile.d/tmout.sh
        echo "declare -xr TMOUT=$var_accounts_tmout" >> /etc/profile.d/tmout.sh
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   User Initialization Files Must Not Run World-Writable Programs   [ref]

Set the mode on files being executed by the user initialization files with the following command:
$ sudo chmod o-w FILE
Rationale:
If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_user_dot_no_world_writable_programs
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict

readarray -t world_writable_files < <(find / -xdev -type f -perm -0002 2> /dev/null)
readarray -t interactive_home_dirs < <(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $6 }' /etc/passwd)

for world_writable in "${world_writable_files[@]}"; do
    for homedir in "${interactive_home_dirs[@]}"; do
        if grep -q -d skip "$world_writable" "$homedir"/.*; then
            chmod o-w $world_writable
            break
        fi
    done
done

Rule   All Interactive Users Home Directories Must Exist   [ref]

Create home directories to all interactive users that currently do not have a home directory assigned. Use the following commands to create the user home directory assigned in /etc/passwd:
$ sudo mkdir /home/USER
Rationale:
If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a Denial of Service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_user_interactive_home_directory_exists
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Get all local users from /etc/passwd
  ansible.builtin.getent:
    database: passwd
    split: ':'
  tags:
  - accounts_user_interactive_home_directory_exists
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create local_users variable from the getent output
  ansible.builtin.set_fact:
    local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
  tags:
  - accounts_user_interactive_home_directory_exists
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure interactive users have a home directory exists
  ansible.builtin.user:
    name: '{{ item.key }}'
    create_home: true
  loop: '{{ local_users }}'
  when:
  - item.value[2]|int >= 1000
  - item.value[2]|int != 65534
  tags:
  - accounts_user_interactive_home_directory_exists
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict

for user in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $1}' /etc/passwd); do
    mkhomedir_helper $user 0077;
done

Rule   All Interactive User Home Directories Must Be Group-Owned By The Primary Group   [ref]

Change the group owner of interactive users home directory to the group found in /etc/passwd. To change the group owner of interactive users home directory, use the following command:
$ sudo chgrp USER_GROUP /home/USER
This rule ensures every home directory related to an interactive user is group-owned by an interactive user. It also ensures that interactive users are group-owners of one and only one home directory.
Warning:  Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the group-ownership of their respective home directories.
Rationale:
If the Group Identifier (GID) of a local interactive users home directory is not the same as the primary GID of the user, this would allow unauthorized access to the users files, and users that share the same group may not be able to access files that they legitimately should.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupownership_home_directories
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Get all local users from /etc/passwd
  ansible.builtin.getent:
    database: passwd
    split: ':'
  tags:
  - file_groupownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create local_users variable from the getent output
  ansible.builtin.set_fact:
    local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
  tags:
  - file_groupownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Test for existence of home directories to avoid creating them, but only fixing
    group ownership
  ansible.builtin.stat:
    path: '{{ item.value[4] }}'
  register: path_exists
  loop: '{{ local_users }}'
  when:
  - item.value[1]|int >= 1000
  - item.value[1]|int != 65534
  tags:
  - file_groupownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure interactive local users are the group-owners of their respective home
    directories
  ansible.builtin.file:
    path: '{{ item.0.value[4] }}'
    group: '{{ item.0.value[2] }}'
  loop: '{{ local_users|zip(path_exists.results)|list }}'
  when: item.1.stat is defined and item.1.stat.exists
  tags:
  - file_groupownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict

awk -F':' '{ if ($3 >= 1000 && $3 != 65534) system("chgrp -f " $4" "$6) }' /etc/passwd

Rule   All Interactive User Home Directories Must Be Owned By The Primary User   [ref]

Change the owner of interactive users home directories to that correct owner. To change the owner of a interactive users home directory, use the following command:
$ sudo chown USER /home/USER
This rule ensures every home directory related to an interactive user is owned by an interactive user. It also ensures that interactive users are owners of one and only one home directory.
Warning:  Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the ownership of their respective home directories.
Rationale:
If a local interactive user does not own their home directory, unauthorized users could access or modify the user's files, and the users may not be able to access their own files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_ownership_home_directories
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Get all local users from /etc/passwd
  ansible.builtin.getent:
    database: passwd
    split: ':'
  tags:
  - file_ownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create local_users variable from the getent output
  ansible.builtin.set_fact:
    local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
  tags:
  - file_ownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Test for existence of home directories to avoid creating them, but only fixing
    ownership
  ansible.builtin.stat:
    path: '{{ item.value[4] }}'
  register: path_exists
  loop: '{{ local_users }}'
  when:
  - item.value[1]|int >= 1000
  - item.value[1]|int != 65534
  tags:
  - file_ownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure interactive local users are the owners of their respective home directories
  ansible.builtin.file:
    path: '{{ item.0.value[4] }}'
    owner: '{{ item.0.value[1] }}'
  loop: '{{ local_users|zip(path_exists.results)|list }}'
  when: item.1.stat is defined and item.1.stat.exists
  tags:
  - file_ownership_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict

awk -F':' '{ if ($3 >= 1000 && $3 != 65534) system("chown -f " $3" "$6) }' /etc/passwd

Rule   All Interactive User Home Directories Must Have mode 0750 Or Less Permissive   [ref]

Change the mode of interactive users home directories to 0750. To change the mode of interactive users home directory, use the following command:
$ sudo chmod 0750 /home/USER
Rationale:
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_home_directories
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Get all local users from /etc/passwd
  ansible.builtin.getent:
    database: passwd
    split: ':'
  tags:
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create local_users variable from the getent output
  ansible.builtin.set_fact:
    local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
  tags:
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Test for existence home directories to avoid creating them.
  ansible.builtin.stat:
    path: '{{ item.value[4] }}'
  register: path_exists
  loop: '{{ local_users }}'
  when:
  - item.value[1]|int >= 1000
  - item.value[1]|int != 65534
  tags:
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure interactive local users have proper permissions on their respective
    home directories
  ansible.builtin.file:
    path: '{{ item.0.value[4] }}'
    mode: u-s,g-w-s,o=-
    follow: false
    recurse: false
  loop: '{{ local_users|zip(path_exists.results)|list }}'
  when: item.1.stat is defined and item.1.stat.exists
  tags:
  - file_permissions_home_directories
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict

for home_dir in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $6 }' /etc/passwd); do
    # Only update the permissions when necessary. This will avoid changing the inode timestamp when
    # the permission is already defined as expected, therefore not impacting in possible integrity
    # check systems that also check inodes timestamps.
    find "$home_dir" -maxdepth 0 -perm /7027 -exec chmod u-s,g-w-s,o=- {} \;
done

Rule   Enable authselect   [ref]

Configure user authentication setup to use the authselect tool. If authselect profile is selected, the rule will enable the minimal profile.
Warning:  If the sudo authselect select command returns an error informing that the chosen profile cannot be selected, it is probably because PAM files have already been modified by the administrator. If this is the case, in order to not overwrite the desired changes made by the administrator, the current PAM settings should be investigated before forcing the selection of the chosen authselect profile.
Rationale:
Authselect is a successor to authconfig. It is a tool to select system authentication and identity sources from a list of supported profiles instead of letting the administrator manually build the PAM stack. That way, it avoids potential breakage of configuration, as it ships several tested profiles that are well tested and supported to solve different use-cases.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_enable_authselect
Identifiers and References

References:  BP28(R31), CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), AC-3, FIA_UAU.1, FIA_AFL.1, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Strategy:configure
- name: XCCDF Value var_authselect_profile # promote to variable
  set_fact:
    var_authselect_profile: !!str minimal
  tags:
    - always

- name: Enable authselect - Select authselect profile
  ansible.builtin.command:
    cmd: authselect select "{{ var_authselect_profile }}"
  register: result_authselect_select
  failed_when: false
  tags:
  - NIST-800-53-AC-3
  - configure_strategy
  - enable_authselect
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Enable authselect - Verify if PAM has been altered
  ansible.builtin.command:
    cmd: rpm -qV pam
  register: result_altered_authselect
  failed_when: false
  when: result_authselect_select.rc != 0
  tags:
  - NIST-800-53-AC-3
  - configure_strategy
  - enable_authselect
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Enable authselect - Informative message based on the authselect integrity
    check
  ansible.builtin.assert:
    that:
    - result_altered_authselect is skipped or result_altered_authselect.rc == 0
    fail_msg:
    - Files in the 'pam' package have been altered, so the authselect configuration
      won't be forced.
  tags:
  - NIST-800-53-AC-3
  - configure_strategy
  - enable_authselect
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Enable authselect - Force authselect profile select
  ansible.builtin.command:
    cmd: authselect select --force "{{ var_authselect_profile }}"
  when:
  - result_authselect_select.rc != 0
  - result_altered_authselect is skipped or result_altered_authselect.rc == 0
  tags:
  - NIST-800-53-AC-3
  - configure_strategy
  - enable_authselect
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed


var_authselect_profile='minimal'


authselect select "$var_authselect_profile"

if test "$?" -ne 0; then
    if rpm --quiet --verify pam; then
        authselect select --force "$var_authselect_profile"
    else
	echo "Files in the 'pam' package have been altered, so the authselect configuration won't be forced" >&2
    fi
fi
Group   System Accounting with auditd   Group contains 11 groups and 58 rules
[ref]   The audit service provides substantial capabilities for recording system activities. By default, the service audits about SELinux AVC denials and certain types of security-relevant events such as system logins, account modifications, and authentication events performed by programs such as sudo. Under its default configuration, auditd has modest disk space requirements, and should not noticeably impact system performance.

NOTE: The Linux Audit daemon auditd can be configured to use the augenrules program to read audit rules files (*.rules) located in /etc/audit/rules.d location and compile them to create the resulting form of the /etc/audit/audit.rules configuration file during the daemon startup (default configuration). Alternatively, the auditd daemon can use the auditctl utility to read audit rules from the /etc/audit/audit.rules configuration file during daemon startup, and load them into the kernel. The expected behavior is configured via the appropriate ExecStartPost directive setting in the /usr/lib/systemd/system/auditd.service configuration file. To instruct the auditd daemon to use the augenrules program to read audit rules (default configuration), use the following setting:
ExecStartPost=-/sbin/augenrules --load
in the /usr/lib/systemd/system/auditd.service configuration file. In order to instruct the auditd daemon to use the auditctl utility to read audit rules, use the following setting:
ExecStartPost=-/sbin/auditctl -R /etc/audit/audit.rules
in the /usr/lib/systemd/system/auditd.service configuration file. Refer to [Service] section of the /usr/lib/systemd/system/auditd.service configuration file for further details.

Government networks often have substantial auditing requirements and auditd can be configured to meet these requirements. Examining some example audit records demonstrates how the Linux audit system satisfies common requirements. The following example from Red Hat Enterprise Linux 7 Documentation available at https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/selinux_users_and_administrators_guide/index#sect-Security-Enhanced_Linux-Fixing_Problems-Raw_Audit_Messages shows the substantial amount of information captured in a two typical "raw" audit messages, followed by a breakdown of the most important fields. In this example the message is SELinux-related and reports an AVC denial (and the associated system call) that occurred when the Apache HTTP Server attempted to access the /var/www/html/file1 file (labeled with the samba_share_t type):
type=AVC msg=audit(1226874073.147:96): avc:  denied  { getattr } for pid=2465 comm="httpd"
path="/var/www/html/file1" dev=dm-0 ino=284133 scontext=unconfined_u:system_r:httpd_t:s0
tcontext=unconfined_u:object_r:samba_share_t:s0 tclass=file

type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)
  • msg=audit(1226874073.147:96)
    • The number in parentheses is the unformatted time stamp (Epoch time) for the event, which can be converted to standard time by using the date command.
  • { getattr }
    • The item in braces indicates the permission that was denied. getattr indicates the source process was trying to read the target file's status information. This occurs before reading files. This action is denied due to the file being accessed having the wrong label. Commonly seen permissions include getattr, read, and write.
  • comm="httpd"
    • The executable that launched the process. The full path of the executable is found in the exe= section of the system call (SYSCALL) message, which in this case, is exe="/usr/sbin/httpd".
  • path="/var/www/html/file1"
    • The path to the object (target) the process attempted to access.
  • scontext="unconfined_u:system_r:httpd_t:s0"
    • The SELinux context of the process that attempted the denied action. In this case, it is the SELinux context of the Apache HTTP Server, which is running in the httpd_t domain.
  • tcontext="unconfined_u:object_r:samba_share_t:s0"
    • The SELinux context of the object (target) the process attempted to access. In this case, it is the SELinux context of file1. Note: the samba_share_t type is not accessible to processes running in the httpd_t domain.
  • From the system call (SYSCALL) message, two items are of interest:
    • success=no: indicates whether the denial (AVC) was enforced or not. success=no indicates the system call was not successful (SELinux denied access). success=yes indicates the system call was successful - this can be seen for permissive domains or unconfined domains, such as initrc_t and kernel_t.
    • exe="/usr/sbin/httpd": the full path to the executable that launched the process, which in this case, is exe="/usr/sbin/httpd".
Group   Configure auditd Rules for Comprehensive Auditing   Group contains 9 groups and 52 rules
[ref]   The auditd program can perform comprehensive monitoring of system activity. This section describes recommended configuration settings for comprehensive auditing, but a full description of the auditing system's capabilities is beyond the scope of this guide. The mailing list linux-audit@redhat.com exists to facilitate community discussion of the auditing system.

The audit subsystem supports extensive collection of events, including:
  • Tracing of arbitrary system calls (identified by name or number) on entry or exit.
  • Filtering by PID, UID, call success, system call argument (with some limitations), etc.
  • Monitoring of specific files for modifications to the file's contents or metadata.

Auditing rules at startup are controlled by the file /etc/audit/audit.rules. Add rules to it to meet the auditing requirements for your organization. Each line in /etc/audit/audit.rules represents a series of arguments that can be passed to auditctl and can be individually tested during runtime. See documentation in /usr/share/doc/audit-VERSION and in the related man pages for more details.

If copying any example audit rulesets from /usr/share/doc/audit-VERSION, be sure to comment out the lines containing arch= which are not appropriate for your system's architecture. Then review and understand the following rules, ensuring rules are activated as needed for the appropriate architecture.

After reviewing all the rules, reading the following sections, and editing as needed, the new rules can be activated as follows:
$ sudo service auditd restart
Group   Record Events that Modify the System's Discretionary Access Controls   Group contains 13 rules
[ref]   At a minimum, the audit system should collect file permission changes for all users and root. Note that the "-F arch=b32" lines should be present even on a 64 bit system. These commands identify system calls for auditing. Even if the system is 64 bit it can still execute 32 bit system calls. Additionally, these rules can be configured in a number of ways while still achieving the desired effect. An example of this is that the "-S" calls could be split up and placed on separate lines, however, this is less efficient. Add the following to /etc/audit/audit.rules:
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b32 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If your system is 64 bit then these lines should be duplicated and the arch=b32 replaced with arch=b64 as follows:
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b64 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

Rule   Record Events that Modify the System's Discretionary Access Controls - chmod   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_chmod
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit chmod tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chmod for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chmod for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of chmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="chmod"
	KEY="perm_mod"
	SYSCALL_GROUPING="chmod fchmod fchmodat"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - chown   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_chown
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit chown tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chown for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for chown for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - chown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of chown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_chown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="chown"
	KEY="perm_mod"
	SYSCALL_GROUPING="chown fchown fchownat lchown"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fchmod   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchmod
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fchmod tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchmod for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchmod for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmod
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmod in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmod
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fchmod"
	KEY="perm_mod"
	SYSCALL_GROUPING="chmod fchmod fchmodat"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fchmodat   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchmodat
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmodat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fchmodat tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmodat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchmodat for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmodat
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmodat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmodat
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmodat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmodat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchmodat for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmodat
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmodat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchmodat
      syscall_grouping:
      - chmod
      - fchmod
      - fchmodat

  - name: Check existence of fchmodat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchmodat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fchmodat"
	KEY="perm_mod"
	SYSCALL_GROUPING="chmod fchmod fchmodat"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fchown   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchown
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fchown tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchown for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchown for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fchown"
	KEY="perm_mod"
	SYSCALL_GROUPING="chown fchown fchownat lchown"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fchownat   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchownat
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchownat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fchownat tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchownat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchownat for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchownat
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchownat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchownat
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchownat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchownat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fchownat for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchownat
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchownat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fchownat
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of fchownat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fchownat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fchownat"
	KEY="perm_mod"
	SYSCALL_GROUPING="chown fchown fchownat lchown"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fremovexattr   [ref]

At a minimum, the audit system should collect file permission changes for all users and root.

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fremovexattr
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000064-GPOS-00033


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fremovexattr tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fremovexattr for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fremovexattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fremovexattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fremovexattr for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fremovexattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fremovexattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fremovexattr"
	KEY="perm_mod"
	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - fsetxattr   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fsetxattr
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000064-GPOS-00033


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit fsetxattr tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fsetxattr for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fsetxattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fsetxattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for fsetxattr for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fsetxattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - fsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of fsetxattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_fsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="fsetxattr"
	KEY="perm_mod"
	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - lchown   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_lchown
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit lchown tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for lchown for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of lchown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of lchown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for lchown for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of lchown in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lchown
      syscall_grouping:
      - chown
      - fchown
      - fchownat
      - lchown

  - name: Check existence of lchown in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lchown
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="lchown"
	KEY="perm_mod"
	SYSCALL_GROUPING="chown fchown fchownat lchown"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - lremovexattr   [ref]

At a minimum, the audit system should collect file permission changes for all users and root.

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_lremovexattr
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit lremovexattr tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for lremovexattr for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lremovexattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lremovexattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for lremovexattr for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lremovexattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lremovexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lremovexattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lremovexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="lremovexattr"
	KEY="perm_mod"
	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - lsetxattr   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_lsetxattr
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000064-GPOS-00033


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit lsetxattr tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for lsetxattr for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lsetxattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lsetxattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for lsetxattr for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lsetxattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - lsetxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of lsetxattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_lsetxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="lsetxattr"
	KEY="perm_mod"
	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - removexattr   [ref]

At a minimum, the audit system should collect file permission changes for all users and root.

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod


If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_removexattr
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_removexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit removexattr tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_removexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for removexattr for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - removexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of removexattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - removexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of removexattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_removexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for removexattr for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - removexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of removexattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - removexattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of removexattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_removexattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="removexattr"
	KEY="perm_mod"
	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Discretionary Access Controls - setxattr   [ref]

At a minimum, the audit system should collect file permission changes for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_setxattr
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_setxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit setxattr tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_setxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for setxattr for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - setxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of setxattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - setxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of setxattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_setxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for setxattr for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - setxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of setxattr in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - setxattr
      syscall_grouping:
      - fremovexattr
      - lremovexattr
      - removexattr
      - fsetxattr
      - lsetxattr
      - setxattr

  - name: Check existence of setxattr in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_dac_modification_setxattr
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="setxattr"
	KEY="perm_mod"
	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Record Execution Attempts to Run ACL Privileged Commands   Group contains 2 rules
[ref]   At a minimum, the audit system should collect the execution of ACL privileged commands for all users and root.

Rule   Record Any Attempts to Run chacl   [ref]

At a minimum, the audit system should collect any execution attempt of the chacl command for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
Rationale:
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_execution_chacl
Identifiers and References

References:  CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - audit_rules_execution_chacl
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for /usr/bin/chacl
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
    set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chacl -F perm=x -F
        auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chacl -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
        -S |,)\w+)+)( -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chacl -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_execution_chacl
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

ACTION_ARCH_FILTERS="-a always,exit"
OTHER_FILTERS="-F path=/usr/bin/chacl -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Any Attempts to Run setfacl   [ref]

At a minimum, the audit system should collect any execution attempt of the setfacl command for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
Rationale:
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_execution_setfacl
Identifiers and References

References:  CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - audit_rules_execution_setfacl
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for /usr/bin/setfacl
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
    set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/setfacl -F perm=x
        -F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/setfacl -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
        -S |,)\w+)+)( -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/setfacl -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_execution_setfacl
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

ACTION_ARCH_FILTERS="-a always,exit"
OTHER_FILTERS="-F path=/usr/bin/setfacl -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Record Execution Attempts to Run SELinux Privileged Commands   Group contains 1 rule
[ref]   At a minimum, the audit system should collect the execution of SELinux privileged commands for all users and root.

Rule   Record Any Attempts to Run chcon   [ref]

At a minimum, the audit system should collect any execution attempt of the chcon command for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
Rationale:
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats.

Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_execution_chcon
Identifiers and References

References:  1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, FAU_GEN.1.1.c, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - audit_rules_execution_chcon
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for /usr/bin/chcon
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
    set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chcon -F perm=x -F
        auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chcon -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
        -S |,)\w+)+)( -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chcon -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - audit_rules_execution_chcon
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

ACTION_ARCH_FILTERS="-a always,exit"
OTHER_FILTERS="-F path=/usr/bin/chcon -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Record File Deletion Events by User   Group contains 4 rules
[ref]   At a minimum, the audit system should collect file deletion events for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat -F auid>=1000 -F auid!=unset -F key=delete

Rule   Ensure auditd Collects File Deletion Events by User - rename   [ref]

At a minimum, the audit system should collect file deletion events for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
Rationale:
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_rename
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-000366, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.7, 10.2.1.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_rename
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit rename tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_rename
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for rename for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - rename
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of rename in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
    set_fact: audit_file="/etc/audit/rules.d/delete.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - rename
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of rename in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_rename
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for rename for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - rename
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of rename in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
    set_fact: audit_file="/etc/audit/rules.d/delete.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - rename
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of rename in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_rename
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="rename"
	KEY="delete"
	SYSCALL_GROUPING="unlink unlinkat rename renameat rmdir"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects File Deletion Events by User - renameat   [ref]

At a minimum, the audit system should collect file deletion events for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
Rationale:
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_renameat
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-000366, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.7, 10.2.1.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_renameat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit renameat tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_renameat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for renameat for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - renameat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of renameat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
    set_fact: audit_file="/etc/audit/rules.d/delete.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - renameat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of renameat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_renameat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for renameat for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - renameat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of renameat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
    set_fact: audit_file="/etc/audit/rules.d/delete.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - renameat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of renameat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_renameat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="renameat"
	KEY="delete"
	SYSCALL_GROUPING="unlink unlinkat rename renameat rmdir"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects File Deletion Events by User - unlinkat   [ref]

At a minimum, the audit system should collect file deletion events for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
Rationale:
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_unlinkat
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-000366, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.7, 10.2.1.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_unlinkat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit unlinkat tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_unlinkat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for unlinkat for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - unlinkat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of unlinkat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
    set_fact: audit_file="/etc/audit/rules.d/delete.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - unlinkat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of unlinkat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_unlinkat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for unlinkat for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - unlinkat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of unlinkat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
    set_fact: audit_file="/etc/audit/rules.d/delete.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - unlinkat
      syscall_grouping:
      - unlink
      - unlinkat
      - rename
      - renameat
      - rmdir

  - name: Check existence of unlinkat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=delete
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_file_deletion_events_unlinkat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="unlinkat"
	KEY="delete"
	SYSCALL_GROUPING="unlink unlinkat rename renameat rmdir"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Record Unauthorized Access Attempts Events to Files (unsuccessful)   Group contains 5 rules
[ref]   At a minimum, the audit system should collect unauthorized file accesses for all users and root. Note that the "-F arch=b32" lines should be present even on a 64 bit system. These commands identify system calls for auditing. Even if the system is 64 bit it can still execute 32 bit system calls. Additionally, these rules can be configured in a number of ways while still achieving the desired effect. An example of this is that the "-S" calls could be split up and placed on separate lines, however, this is less efficient. Add the following to /etc/audit/audit.rules:
-a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If your system is 64 bit then these lines should be duplicated and the arch=b32 replaced with arch=b64 as follows:
-a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access

Rule   Record Unsuccessful Access Attempts to Files - creat   [ref]

At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_creat
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.4, Req-10.2.1, 10.2.1.1, 10.2.1.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_creat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit creat tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_creat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for creat EACCES for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_creat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for creat EACCES for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_creat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for creat EPERM for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_creat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for creat EPERM for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - creat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of creat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_creat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="creat"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EACCES"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EPERM"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Unsuccessful Access Attempts to Files - ftruncate   [ref]

At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_ftruncate
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.4, Req-10.2.1, 10.2.1.1, 10.2.1.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_ftruncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit ftruncate tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_ftruncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for ftruncate EACCES for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_ftruncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for ftruncate EACCES for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_ftruncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for ftruncate EPERM for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_ftruncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for ftruncate EPERM for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - ftruncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of ftruncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_ftruncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="ftruncate"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EACCES"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EPERM"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Unsuccessful Access Attempts to Files - open   [ref]

At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_open
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.4, Req-10.2.1, 10.2.1.1, 10.2.1.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_open
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit open tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_open
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for open EACCES for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_open
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for open EACCES for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_open
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for open EPERM for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_open
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for open EPERM for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - open
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of open in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_open
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="open"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EACCES"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EPERM"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Unsuccessful Access Attempts to Files - openat   [ref]

At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_openat
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.4, Req-10.2.1, 10.2.1.1, 10.2.1.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_openat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit openat tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_openat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for openat EACCES for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_openat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for openat EACCES for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_openat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for openat EPERM for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_openat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for openat EPERM for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - openat
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of openat in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_openat
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="openat"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EACCES"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EPERM"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Unsuccessful Access Attempts to Files - truncate   [ref]

At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale:
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_truncate
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.4, Req-10.2.1, 10.2.1.1, 10.2.1.4, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_truncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit truncate tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_truncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for truncate EACCES for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_truncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for truncate EACCES for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_truncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for truncate EPERM for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_truncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for truncate EPERM for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
    set_fact: audit_file="/etc/audit/rules.d/access.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - truncate
      syscall_grouping:
      - creat
      - ftruncate
      - truncate
      - open
      - openat
      - open_by_handle_at

  - name: Check existence of truncate in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
        -F auid>=1000 -F auid!=unset -F key=access
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.1
  - PCI-DSS-Req-10.2.4
  - PCI-DSSv4-10.2.1.1
  - PCI-DSSv4-10.2.1.4
  - audit_rules_unsuccessful_file_modification_truncate
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="truncate"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EACCES"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F exit=-EPERM"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Record Information on Kernel Modules Loading and Unloading   Group contains 2 rules
[ref]   To capture kernel module loading and unloading events, use following lines, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S init_module,delete_module -F key=modules
Place to add the lines depends on a way auditd daemon is configured. If it is configured to use the augenrules program (the default), add the lines to a file with suffix .rules in the directory /etc/audit/rules.d. If the auditd daemon is configured to use the auditctl utility, add the lines to file /etc/audit/audit.rules.

Rule   Ensure auditd Collects Information on Kernel Module Unloading - delete_module   [ref]

To capture kernel module unloading events, use following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S delete_module -F key=modules
Place to add the line depends on a way auditd daemon is configured. If it is configured to use the augenrules program (the default), add the line to a file with suffix .rules in the directory /etc/audit/rules.d. If the auditd daemon is configured to use the auditctl utility, add the line to file /etc/audit/audit.rules.
Rationale:
The removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_delete
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.7, 10.2.1.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20delete_module%20-k%20module-change%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20delete_module%20-k%20module-change%0A
        mode: 0600
        path: /etc/audit/rules.d/75-kernel-module-loading-delete.rules
        overwrite: true

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
# Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
#       it's required on a 64-bit system to check also for the presence
#       of 32-bit's equivalent of the corresponding rule.
#       (See `man 7 audit.rules` for details )
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	
	AUID_FILTERS=""
	
	SYSCALL="delete_module"
	KEY="modules"
	SYSCALL_GROUPING="delete_module"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects Information on Kernel Module Loading - init_module   [ref]

To capture kernel module loading events, use following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S init_module -F key=modules
Place to add the line depends on a way auditd daemon is configured. If it is configured to use the augenrules program (the default), add the line to a file with suffix .rules in the directory /etc/audit/rules.d. If the auditd daemon is configured to use the auditctl utility, add the line to file /etc/audit/audit.rules.
Rationale:
The addition of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_init
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.7, 10.2.1.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20init_module%20-k%20module-change%0A-a%20always%2Cexit%20-F%20arch%3Db64%20-S%20init_module%20-k%20module-change%0A
        mode: 0600
        path: /etc/audit/rules.d/75-kernel-module-loading-init.rules
        overwrite: true

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
# Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
#       it's required on a 64-bit system to check also for the presence
#       of 32-bit's equivalent of the corresponding rule.
#       (See `man 7 audit.rules` for details )
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	
	AUID_FILTERS=""
	
	SYSCALL="init_module"
	KEY="modules"
	SYSCALL_GROUPING="init_module finit_module"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Record Attempts to Alter Logon and Logout Events   Group contains 2 rules
Group   Record Information on the Use of Privileged Commands   Group contains 2 rules
[ref]   At a minimum, the audit system should collect the execution of privileged commands for all users and root.

Rule   Ensure auditd Collects Information on the Use of Privileged Commands   [ref]

The audit system should collect information about usage of privileged commands for all users. These are commands with suid or sgid bits on and they are specially risky in local block device partitions not mounted with noexec and nosuid options. Therefore, these partitions should be first identified by the following command:
findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,) | grep -Pv "noexec|nosuid"
For all partitions listed by the previous command, it is necessary to search for setuid / setgid programs using the following command:
$ sudo find PARTITION -xdev -perm /6000 -type f 2>/dev/null
For each setuid / setgid program identified by the previous command, an audit rule must be present in the appropriate place using the following line structure:
-a always,exit -F path=PROG_PATH -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup, add the line to a file with suffix .rules in the /etc/audit/rules.d directory, replacing the PROG_PATH part with the full path of that setuid / setgid identified program. If the auditd daemon is configured to use the auditctl utility instead, add the line to the /etc/audit/audit.rules file, also replacing the PROG_PATH part with the full path of that setuid / setgid identified program.
Warning:  This rule checks for multiple syscalls related to privileged commands. If needed to check specific privileged commands, other more specific rules should be considered. For example:
  • audit_rules_privileged_commands_su
  • audit_rules_privileged_commands_umount
  • audit_rules_privileged_commands_passwd
Warning:  Note that OVAL check and Bash / Ansible remediation of this rule explicitly excludes file systems mounted at
/proc
directory and its subdirectories. It is a virtual file system and it doesn't contain executable applications. At the same time, interacting with this file system during check or remediation caused undesirable errors.
Rationale:
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern that can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats.

Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_privileged_commands
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO08.04, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.05, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-002234, 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.5, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.3.4.5.9, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 3.9, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, 0582, 0584, 05885, 0586, 0846, 0957, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.1, A.16.1.2, A.16.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.3, A.6.2.1, A.6.2.2, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-2, DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, DE.DP-4, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, RS.CO-2, Req-10.2.2, 10.2.1.2, SRG-OS-000327-GPOS-00127


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSSv4-10.2.1.2
  - audit_rules_privileged_commands
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure auditd Collects Information on the Use of Privileged Commands - Set
    List of Mount Points Which Permits Execution of Privileged Commands
  ansible.builtin.set_fact:
    privileged_mount_points: '{{(ansible_facts.mounts | rejectattr(''options'', ''search'',
      ''noexec|nosuid'') | rejectattr(''mount'', ''match'', ''/proc($|/.*$)'') | map(attribute=''mount'')
      | list ) }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSSv4-10.2.1.2
  - audit_rules_privileged_commands
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure auditd Collects Information on the Use of Privileged Commands - Search
    for Privileged Commands in Eligible Mount Points
  ansible.builtin.shell:
    cmd: find {{ item }} -xdev -perm /6000 -type f 2>/dev/null
  register: result_privileged_commands_search
  changed_when: false
  failed_when: false
  with_items: '{{ privileged_mount_points }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSSv4-10.2.1.2
  - audit_rules_privileged_commands
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure auditd Collects Information on the Use of Privileged Commands - Set
    List of Privileged Commands Found in Eligible Mount Points
  ansible.builtin.set_fact:
    privileged_commands: '{{( result_privileged_commands_search.results | map(attribute=''stdout_lines'')
      | select() | list )[-1] }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSSv4-10.2.1.2
  - audit_rules_privileged_commands
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure auditd Collects Information on the Use of Privileged Commands - Privileged
    Commands are Present in the System
  block:

  - name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
      Rules for All Privileged Commands in augenrules Format
    ansible.builtin.lineinfile:
      path: /etc/audit/rules.d/privileged.rules
      line: -a always,exit -F path={{ item }} -F perm=x -F auid>=1000 -F auid!=unset
        -F key=privileged
      regexp: ^.*path={{ item | regex_escape() }} .*$
      create: true
    with_items:
    - '{{ privileged_commands }}'

  - name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
      Rules for All Privileged Commands in auditctl Format
    ansible.builtin.lineinfile:
      path: /etc/audit/audit.rules
      line: -a always,exit -F path={{ item }} -F perm=x -F auid>=1000 -F auid!=unset
        -F key=privileged
      regexp: ^.*path={{ item | regex_escape() }} .*$
      create: true
    with_items:
    - '{{ privileged_commands }}'

  - name: Ensure auditd Collects Information on the Use of Privileged Commands - Search
      for Duplicated Rules in Other Files
    ansible.builtin.find:
      paths: /etc/audit/rules.d
      recurse: false
      contains: ^-a always,exit -F path={{ item }} .*$
      patterns: '*.rules'
    with_items:
    - '{{ privileged_commands }}'
    register: result_augenrules_files

  - name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
      Rules for Privileged Commands are Defined Only in One File
    ansible.builtin.lineinfile:
      path: '{{ item.1.path }}'
      regexp: ^-a always,exit -F path={{ item.0.item }} .*$
      state: absent
    with_subelements:
    - '{{ result_augenrules_files.results }}'
    - files
    when:
    - item.1.path != '/etc/audit/rules.d/privileged.rules'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - privileged_commands is defined
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSSv4-10.2.1.2
  - audit_rules_privileged_commands
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

ACTION_ARCH_FILTERS="-a always,exit"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""

FILTER_NODEV=$(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
PARTITIONS=$(findmnt -n -l -k -it $FILTER_NODEV | grep -Pv "noexec|nosuid|/proc($|/.*$)" | awk '{ print $1 }')
for PARTITION in $PARTITIONS; do
  PRIV_CMDS=$(find "${PARTITION}" -xdev -perm /6000 -type f 2>/dev/null)
  for PRIV_CMD in $PRIV_CMDS; do
    OTHER_FILTERS="-F path=$PRIV_CMD -F perm=x"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()


    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0640 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()



    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
  done
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects Information on the Use of Privileged Commands - usermod   [ref]

At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
Rationale:
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats.

Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_privileged_commands_usermod
Identifiers and References

References:  CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - audit_rules_privileged_commands_usermod
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for /usr/sbin/usermod
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
    set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/sbin/usermod -F perm=x
        -F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/sbin/usermod -F
        perm=x -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

  - name: Check existence of  in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
        path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
        -S |,)\w+)+)( -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset
        (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/sbin/usermod -F
        perm=x -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_privileged_commands_usermod
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

ACTION_ARCH_FILTERS="-a always,exit"
OTHER_FILTERS="-F path=/usr/sbin/usermod -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Records Events that Modify Date and Time Information   Group contains 5 rules
[ref]   Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time. All changes to the system time should be audited.

Rule   Record attempts to alter time through adjtimex   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale:
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_time_adjtimex
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-001487, CCI-000169, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 10.6.3


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -a%20always%2Cexit%20-F%20arch%3Db64%20-S%20adjtimex%20-k%20audit_time_rules%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20adjtimex%20-k%20audit_time_rules%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-syscall-adjtimex.rules
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_adjtimex
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set architecture for audit tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_adjtimex
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for adjtimex for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - adjtimex
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of adjtimex in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - adjtimex
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of adjtimex in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_adjtimex
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for adjtimex for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - adjtimex
      syscall_grouping:
      - adjtimex
      - settimeofday

  - name: Check existence of adjtimex in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - adjtimex
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of adjtimex in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_adjtimex
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
    # Create expected audit group and audit rule form for particular system call & architecture
    if [ ${ARCH} = "b32" ]
    then
        ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
        # stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
        # so append it to the list of time group system calls to be audited
        SYSCALL="adjtimex settimeofday stime"
        SYSCALL_GROUPING="adjtimex settimeofday stime"
    elif [ ${ARCH} = "b64" ]
    then
        ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
        # stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
        # therefore don't add it to the list of time group system calls to be audited
        SYSCALL="adjtimex settimeofday"
        SYSCALL_GROUPING="adjtimex settimeofday"
    fi
    OTHER_FILTERS=""
    AUID_FILTERS=""
    KEY="audit_time_rules"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()


    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0640 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()



    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Attempts to Alter Time Through clock_settime   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale:
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_time_clock_settime
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-001487, CCI-000169, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 10.6.3


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -a%20always%2Cexit%20-F%20arch%3Db64%20-S%20clock_settime%20-F%20a0%3D0x0%20-k%20time-change%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20clock_settime%20-F%20a0%3D0x0%20-k%20time-change%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-syscall-clock-settime.rules
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_clock_settime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set architecture for audit tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_clock_settime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for clock_settime for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - clock_settime
      syscall_grouping: []

  - name: Check existence of clock_settime in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/time-change.rules
    set_fact: audit_file="/etc/audit/rules.d/time-change.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F a0=0x0 -F
        key=time-change
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - clock_settime
      syscall_grouping: []

  - name: Check existence of clock_settime in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F a0=0x0 -F
        key=time-change
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_clock_settime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for clock_settime for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - clock_settime
      syscall_grouping: []

  - name: Check existence of clock_settime in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/time-change.rules
    set_fact: audit_file="/etc/audit/rules.d/time-change.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F a0=0x0 -F
        key=time-change
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - clock_settime
      syscall_grouping: []

  - name: Check existence of clock_settime in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F a0=0x0 -F
        key=time-change
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_clock_settime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS="-F a0=0x0"
	AUID_FILTERS=""
	SYSCALL="clock_settime"
	KEY="time-change"
	SYSCALL_GROUPING=""
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record attempts to alter time through settimeofday   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale:
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_time_settimeofday
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-001487, CCI-000169, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 10.6.3


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -a%20always%2Cexit%20-F%20arch%3Db64%20-S%20settimeofday%20-k%20audit_time_rules%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20settimeofday%20-k%20audit_time_rules%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-syscall-settimeofday.rules
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_settimeofday
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set architecture for audit tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_settimeofday
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for settimeofday for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - settimeofday
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of settimeofday in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - settimeofday
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of settimeofday in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_settimeofday
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for settimeofday for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - settimeofday
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of settimeofday in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - settimeofday
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of settimeofday in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_settimeofday
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
    # Create expected audit group and audit rule form for particular system call & architecture
    if [ ${ARCH} = "b32" ]
    then
        ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
        # stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
        # so append it to the list of time group system calls to be audited
        SYSCALL="adjtimex settimeofday stime"
        SYSCALL_GROUPING="adjtimex settimeofday stime"
    elif [ ${ARCH} = "b64" ]
    then
        ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
        # stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
        # therefore don't add it to the list of time group system calls to be audited
        SYSCALL="adjtimex settimeofday"
        SYSCALL_GROUPING="adjtimex settimeofday"
    fi
    OTHER_FILTERS=""
    AUID_FILTERS=""
    KEY="audit_time_rules"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()


    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0640 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()



    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Attempts to Alter Time Through stime   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d for both 32 bit and 64 bit systems:
-a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32 bit and 64 bit systems). If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file for both 32 bit and 64 bit systems:
-a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32 bit and 64 bit systems). The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined system calls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale:
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_time_stime
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-001487, CCI-000169, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 10.6.3


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -a%20always%2Cexit%20-F%20arch%3Db64%20-S%20stime%20-k%20audit_time_rules%0A-a%20always%2Cexit%20-F%20arch%3Db32%20-S%20stime%20-k%20audit_time_rules%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-syscall-stime.rules
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_stime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Perform remediation of Audit rules for stime syscall for x86 platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - stime
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of stime in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - stime
      syscall_grouping:
      - adjtimex
      - settimeofday
      - stime

  - name: Check existence of stime in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - audit_rules_time_stime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
    # Create expected audit group and audit rule form for particular system call & architecture
    if [ ${ARCH} = "b32" ]
    then
        ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
        # stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
        # so append it to the list of time group system calls to be audited
        SYSCALL="adjtimex settimeofday stime"
        SYSCALL_GROUPING="adjtimex settimeofday stime"
    elif [ ${ARCH} = "b64" ]
    then
        ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
        # stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
        # therefore don't add it to the list of time group system calls to be audited
        SYSCALL="adjtimex settimeofday"
        SYSCALL_GROUPING="adjtimex settimeofday"
    fi
    OTHER_FILTERS=""
    AUID_FILTERS=""
    KEY="audit_time_rules"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()


    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0640 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()



    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod o-rwx ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Attempts to Alter the localtime File   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-w /etc/localtime -p wa -k audit_time_rules
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-w /etc/localtime -p wa -k audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport and should always be used.
Rationale:
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_time_watch_localtime
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-001487, CCI-000169, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 10.6.3, 10.6.3


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -w%20/etc/localtime%20-p%20wa%20-k%20audit_time_rules%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-etclocaltime-wa-audit_time_rules.rules
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/localtime already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/localtime\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_time_rules
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_time_rules$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_time_rules.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_time_rules.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/localtime in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/localtime -p wa -k audit_time_rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/localtime already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/localtime\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/localtime in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/localtime -p wa -k audit_time_rules
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.2.b
  - PCI-DSSv4-10.6.3
  - PCI-DSSv4-10.6.3
  - audit_rules_time_watch_localtime
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/localtime" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/localtime $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/localtime$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/localtime -p wa -k audit_time_rules" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_time_rules.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/localtime" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_time_rules.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_time_rules.rules"
    # If the audit_time_rules.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/localtime" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/localtime $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/localtime$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/localtime -p wa -k audit_time_rules" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Make the auditd Configuration Immutable   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d in order to make the auditd configuration immutable:
-e 2
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file in order to make the auditd configuration immutable:
-e 2
With this setting, a reboot will be required to change any audit rules.
Rationale:
Making the audit configuration immutable prevents accidental as well as malicious modification of the audit rules, although it may be problematic if legitimate changes are needed during system operation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_immutable
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 3.4.3, CCI-000162, CCI-000163, CCI-000164, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.310(a)(2)(iv), 164.312(d), 164.310(d)(2)(iii), 164.312(b), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5.2, 10.3.2, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,-e%202%0A
        mode: 0600
        path: /etc/audit/rules.d/90-immutable.rules
        overwrite: true

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.4.3
  - NIST-800-53-AC-6(9)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - audit_rules_immutable
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Collect all files from /etc/audit/rules.d with .rules extension
  find:
    paths: /etc/audit/rules.d/
    patterns: '*.rules'
  register: find_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.4.3
  - NIST-800-53-AC-6(9)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - audit_rules_immutable
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Remove the -e option from all Audit config files
  lineinfile:
    path: '{{ item }}'
    regexp: ^\s*(?:-e)\s+.*$
    state: absent
  loop: '{{ find_rules_d.files | map(attribute=''path'') | list + [''/etc/audit/audit.rules'']
    }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.4.3
  - NIST-800-53-AC-6(9)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - audit_rules_immutable
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add Audit -e option into /etc/audit/rules.d/immutable.rules and /etc/audit/audit.rules
  lineinfile:
    path: '{{ item }}'
    create: true
    line: -e 2
    mode: o-rwx
  loop:
  - /etc/audit/audit.rules
  - /etc/audit/rules.d/immutable.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.4.3
  - NIST-800-53-AC-6(9)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3.2
  - audit_rules_immutable
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Traverse all of:
#
# /etc/audit/audit.rules,			(for auditctl case)
# /etc/audit/rules.d/*.rules			(for augenrules case)
#
# files to check if '-e .*' setting is present in that '*.rules' file already.
# If found, delete such occurrence since auditctl(8) manual page instructs the
# '-e 2' rule should be placed as the last rule in the configuration
find /etc/audit /etc/audit/rules.d -maxdepth 1 -type f -name '*.rules' -exec sed -i '/-e[[:space:]]\+.*/d' {} ';'

# Append '-e 2' requirement at the end of both:
# * /etc/audit/audit.rules file 		(for auditctl case)
# * /etc/audit/rules.d/immutable.rules		(for augenrules case)

for AUDIT_FILE in "/etc/audit/audit.rules" "/etc/audit/rules.d/immutable.rules"
do
	echo '' >> $AUDIT_FILE
	echo '# Set the audit.rules configuration immutable per security requirements' >> $AUDIT_FILE
	echo '# Reboot is required to change audit rules once this setting is applied' >> $AUDIT_FILE
	echo '-e 2' >> $AUDIT_FILE
	chmod o-rwx $AUDIT_FILE
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Mandatory Access Controls   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-w /etc/selinux/ -p wa -k MAC-policy
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-w /etc/selinux/ -p wa -k MAC-policy
Rationale:
The system's mandatory access policy (SELinux) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_mac_modification
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.8, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5, 10.3.4


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -w%20/etc/selinux/%20-p%20wa%20-k%20MAC-policy%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-etcselinux-wa-MAC-policy.rules
        overwrite: true

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/selinux/ already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/selinux/\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key MAC-policy
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)MAC-policy$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/MAC-policy.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/MAC-policy.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/selinux/ in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/selinux/ -p wa -k MAC-policy
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/selinux/ already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/selinux/\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/selinux/ in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/selinux/ -p wa -k MAC-policy
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_mac_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/selinux/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/MAC-policy.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/selinux/" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/MAC-policy.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/MAC-policy.rules"
    # If the MAC-policy.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/selinux/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Mandatory Access Controls in usr/share   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-w /usr/share/selinux/ -p wa -k MAC-policy
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-w /usr/share/selinux/ -p wa -k MAC-policy
Rationale:
The system's mandatory access policy (SELinux) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_mac_modification_usr_share
Identifiers and References

References:  APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.8, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.5.5


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /usr/share/selinux/ already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/usr/share/selinux/\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key MAC-policy
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)MAC-policy$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/MAC-policy.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/MAC-policy.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /usr/share/selinux/ in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /usr/share/selinux/ -p wa -k MAC-policy
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /usr/share/selinux/ already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/usr/share/selinux/\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /usr/share/selinux/ in /etc/audit/audit.rules
  lineinfile:
    line: -w /usr/share/selinux/ -p wa -k MAC-policy
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - NIST-800-171-3.1.8
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - audit_rules_mac_modification_usr_share
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/usr/share/selinux/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/usr/share/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/usr/share/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /usr/share/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/MAC-policy.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/usr/share/selinux/" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/MAC-policy.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/MAC-policy.rules"
    # If the MAC-policy.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/usr/share/selinux/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/usr/share/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/usr/share/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /usr/share/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects Information on Exporting to Media (successful)   [ref]

At a minimum, the audit system should collect media exportation events for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
Rationale:
The unauthorized exportation of data to external media could result in an information leak where classified information, Privacy Act information, and intellectual property could be lost. An audit trail should be created each time a filesystem is mounted to help identify and guard against information loss.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_media_export
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, 10.2.1.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_media_export
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Set architecture for audit mount tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_media_export
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for mount for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - mount
      syscall_grouping: []

  - name: Check existence of mount in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - mount
      syscall_grouping: []

  - name: Check existence of mount in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_media_export
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Perform remediation of Audit rules for mount for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - mount
      syscall_grouping: []

  - name: Check existence of mount in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
    set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
        |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - mount
      syscall_grouping: []

  - name: Check existence of mount in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
        key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
        -F auid!=unset -F key=perm_mod
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.7
  - PCI-DSSv4-10.2.1.7
  - audit_rules_media_export
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
	SYSCALL="mount"
	KEY="perm_mod"
	SYSCALL_GROUPING=""

	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify the System's Network Environment   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
-w /etc/issue -p wa -k audit_rules_networkconfig_modification
-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
-w /etc/hosts -p wa -k audit_rules_networkconfig_modification
-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file, setting ARCH to either b32 or b64 as appropriate for your system:
-a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
-w /etc/issue -p wa -k audit_rules_networkconfig_modification
-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
-w /etc/hosts -p wa -k audit_rules_networkconfig_modification
-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
Rationale:
The network environment should not be modified by anything other than administrator action. Any change to network parameters should be audited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_networkconfig_modification
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, 10.3.4


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set architecture for audit tasks
  set_fact:
    audit_arch: b64
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
    == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Remediate audit rules for network configuration for 32bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - sethostname
      - setdomainname
      syscall_grouping:
      - sethostname
      - setdomainname

  - name: Check existence of sethostname, setdomainname in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - sethostname
      - setdomainname
      syscall_grouping:
      - sethostname
      - setdomainname

  - name: Check existence of sethostname, setdomainname in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Remediate audit rules for network configuration for 64bit platform
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - sethostname
      - setdomainname
      syscall_grouping:
      - sethostname
      - setdomainname

  - name: Check existence of sethostname, setdomainname in /etc/audit/rules.d/
    find:
      paths: /etc/audit/rules.d
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: '*.rules'
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Reset syscalls found per file
    set_fact:
      syscalls_per_file: {}
      found_paths_dict: {}

  - name: Declare syscalls found per file
    set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
      :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
    loop: '{{ find_command.results | selectattr(''matched'') | list }}'

  - name: Declare files where syscalls were found
    set_fact: found_paths="{{ find_command.results | map(attribute='files') | flatten
      | map(attribute='path') | list }}"

  - name: Count occurrences of syscalls in paths
    set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
      0) }) }}"
    loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
      | list }}'

  - name: Get path with most syscalls
    set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
      | last).key }}"
    when: found_paths | length >= 1

  - name: No file with syscall found, set path to /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
    set_fact: audit_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
    when: found_paths | length == 0

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
        | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls:
      - sethostname
      - setdomainname
      syscall_grouping:
      - sethostname
      - setdomainname

  - name: Check existence of sethostname, setdomainname in /etc/audit/audit.rules
    find:
      paths: /etc/audit
      contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
        |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
      patterns: audit.rules
    register: find_command
    loop: '{{ (syscall_grouping + syscalls) | unique }}'

  - name: Set path to /etc/audit/audit.rules
    set_fact: audit_file="/etc/audit/audit.rules"

  - name: Declare found syscalls
    set_fact: syscalls_found="{{ find_command.results | selectattr('matched') | map(attribute='item')
      | list }}"

  - name: Declare missing syscalls
    set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found) }}"

  - name: Replace the audit rule in {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
        join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
      line: \1\2\3{{ missing_syscalls | join("\3") }}\4
      backrefs: true
      state: present
    when: syscalls_found | length > 0 and missing_syscalls | length > 0

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - audit_arch == "b64"
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/issue already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/issue\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_networkconfig_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules as the
    recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/issue in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/issue already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/issue\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/issue in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/issue.net already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/issue.net\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_networkconfig_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules as the
    recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/issue.net in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/issue.net already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/issue.net\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/issue.net in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/hosts already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/hosts\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_networkconfig_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules as the
    recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/hosts in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/hosts already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/hosts\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/hosts in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sysconfig/network already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/sysconfig/network\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_networkconfig_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules as the
    recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sysconfig/network in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sysconfig/network already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/sysconfig/network\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sysconfig/network in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.5
  - PCI-DSSv4-10.3.4
  - audit_rules_networkconfig_modification
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	OTHER_FILTERS=""
	AUID_FILTERS=""
	SYSCALL="sethostname setdomainname"
	KEY="audit_rules_networkconfig_modification"
	SYSCALL_GROUPING="sethostname setdomainname"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

# Then perform the remediations for the watch rules
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/issue" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/issue$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/issue -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/issue" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
    # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/issue" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/issue$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/issue -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/issue.net" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue.net $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/issue.net$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/issue.net" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
    # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/issue.net" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue.net $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/issue.net$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/hosts" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/hosts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/hosts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/hosts -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/hosts" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
    # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/hosts" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/hosts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/hosts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/hosts -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sysconfig/network" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
    # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Attempts to Alter Process and Session Initiation Information   [ref]

The audit system already collects process information for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d in order to watch for attempted manual edits of files involved in storing such process information:
-w /var/run/utmp -p wa -k session
-w /var/log/btmp -p wa -k session
-w /var/log/wtmp -p wa -k session
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file in order to watch for attempted manual edits of files involved in storing such process information:
-w /var/run/utmp -p wa -k session
-w /var/log/btmp -p wa -k session
-w /var/log/wtmp -p wa -k session
Rationale:
Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_session_events
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, 0582, 0584, 05885, 0586, 0846, 0957, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.3, 10.2.1.3


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---


apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ %0A-w%20/var/run/utmp%20-p%20wa%20-k%20session%0A-w%20/var/log/btmp%20-p%20wa%20-k%20session%0A-w%20/var/log/wtmp%20-p%20wa%20-k%20session%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-audit-session-events.rules
        overwrite: true

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/run/utmp already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/var/run/utmp\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key session
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)session$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/session.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/session.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/run/utmp in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /var/run/utmp -p wa -k session
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/run/utmp already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/var/run/utmp\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/run/utmp in /etc/audit/audit.rules
  lineinfile:
    line: -w /var/run/utmp -p wa -k session
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/log/btmp already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/var/log/btmp\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key session
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)session$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/session.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/session.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/log/btmp in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /var/log/btmp -p wa -k session
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/log/btmp already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/var/log/btmp\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/log/btmp in /etc/audit/audit.rules
  lineinfile:
    line: -w /var/log/btmp -p wa -k session
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/log/wtmp already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/var/log/wtmp\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key session
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)session$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/session.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/session.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/log/wtmp in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /var/log/wtmp -p wa -k session
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/log/wtmp already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/var/log/wtmp\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/log/wtmp in /etc/audit/audit.rules
  lineinfile:
    line: -w /var/log/wtmp -p wa -k session
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.3
  - PCI-DSSv4-10.2.1.3
  - audit_rules_session_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/run/utmp" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/run/utmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/run/utmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/run/utmp -p wa -k session" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/run/utmp" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/session.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/session.rules"
    # If the session.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/run/utmp" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/run/utmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/run/utmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/run/utmp -p wa -k session" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/log/btmp" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/btmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/log/btmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/log/btmp -p wa -k session" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/btmp" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/session.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/session.rules"
    # If the session.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/log/btmp" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/btmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/log/btmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/log/btmp -p wa -k session" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/log/wtmp" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/wtmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/log/wtmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/log/wtmp -p wa -k session" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/wtmp" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/session.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/session.rules"
    # If the session.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/log/wtmp" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/wtmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/log/wtmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/log/wtmp -p wa -k session" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects System Administrator Actions - /etc/sudoers   [ref]

At a minimum, the audit system should collect administrator actions for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-w /etc/sudoers -p wa -k actions
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-w /etc/sudoers -p wa -k actions
Rationale:
The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes. Editing the sudoers file may be sign of an attacker trying to establish persistent methods to a system, auditing the editing of the sudoers files mitigates this risk.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_sudoers
Identifiers and References

References:  CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-002130, CCI-002132, CCI-002884, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key actions
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)actions$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/actions.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/actions.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/sudoers -p wa -k actions
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/sudoers -p wa -k actions
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - audit_rules_sudoers
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/actions.rules"
    # If the actions.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects System Administrator Actions - /etc/sudoers.d/   [ref]

At a minimum, the audit system should collect administrator actions for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-w /etc/sudoers.d/ -p wa -k actions
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-w /etc/sudoers.d/ -p wa -k actions
Rationale:
The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes. Editing the sudoers file may be sign of an attacker trying to establish persistent methods to a system, auditing the editing of the sudoers files mitigates this risk.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_sudoers_d
Identifiers and References

References:  CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-002130, CCI-002132, CCI-002884, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers.d/ already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key actions
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)actions$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/actions.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/actions.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers.d/ in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/sudoers.d/ -p wa -k actions
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers.d/ already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers.d/ in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/sudoers.d/ -p wa -k actions
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers.d/" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/actions.rules"
    # If the actions.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events When Privileged Executables Are Run   [ref]

Verify the system generates an audit record when privileged functions are executed. If audit is using the "auditctl" tool to load the rules, run the following command:
$ sudo grep execve /etc/audit/audit.rules
If audit is using the "augenrules" tool to load the rules, run the following command:
$ sudo grep -r execve /etc/audit/rules.d
-a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid
-a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid
If both the "b32" and "b64" audit rules for "SUID" files are not defined, this is a finding. If both the "b32" and "b64" audit rules for "SGID" files are not defined, this is a finding.
Warning:  Note that these rules can be configured in a number of ways while still achieving the desired effect.
Rationale:
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_suid_privilege_function
Identifiers and References

References:  CCI-001814, CCI-001882, CCI-001889, CCI-001880, CCI-001881, CCI-001878, CCI-001879, CCI-001875, CCI-001877, CCI-001914, CCI-002233, CCI-002234, CM-5(1), AU-7(a), AU-7(b), AU-8(b), AU-12(3), AC-6(9), SRG-OS-000326-GPOS-00126, SRG-OS-000327-GPOS-00127


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Service facts
  ansible.builtin.service_facts: null
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check the rules script being used
  ansible.builtin.command: grep '^ExecStartPost' /usr/lib/systemd/system/auditd.service
  register: check_rules_scripts_result
  changed_when: false
  failed_when: false
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set suid_audit_rules fact
  ansible.builtin.set_fact:
    suid_audit_rules:
    - rule: -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid
      regex: ^[\s]*-a[\s]+always,exit[\s]+-F[\s]+arch=b32[\s]+-S[\s]+execve[\s]+-C[\s]+gid!=egid[\s]+-F[\s]+egid=0[\s]+(?:-k[\s]+|-F[\s]+key=)[\S]+[\s]*$
    - rule: -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid
      regex: ^[\s]*-a[\s]+always,exit[\s]+-F[\s]+arch=b64[\s]+-S[\s]+execve[\s]+-C[\s]+gid!=egid[\s]+-F[\s]+egid=0[\s]+(?:-k[\s]+|-F[\s]+key=)[\S]+[\s]*$
    - rule: -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid
      regex: ^[\s]*-a[\s]+always,exit[\s]+-F[\s]+arch=b32[\s]+-S[\s]+execve[\s]+-C[\s]+uid!=euid[\s]+-F[\s]+euid=0[\s]+(?:-k[\s]+|-F[\s]+key=)[\S]+[\s]*$
    - rule: -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid
      regex: ^[\s]*-a[\s]+always,exit[\s]+-F[\s]+arch=b64[\s]+-S[\s]+execve[\s]+-C[\s]+uid!=euid[\s]+-F[\s]+euid=0[\s]+(?:-k[\s]+|-F[\s]+key=)[\S]+[\s]*$
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Update /etc/audit/rules.d/privileged.rules to audit privileged functions
  ansible.builtin.lineinfile:
    path: /etc/audit/rules.d/privileged.rules
    line: '{{  item.rule  }}'
    regexp: '{{ item.regex }}'
    create: true
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"auditd.service" in ansible_facts.services'
  - '"augenrules" in check_rules_scripts_result.stdout'
  register: augenrules_audit_rules_privilege_function_update_result
  with_items: '{{ suid_audit_rules }}'
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Update Update /etc/audit/audit.rules to audit privileged functions
  ansible.builtin.lineinfile:
    path: /etc/audit/audit.rules
    line: '{{  item.rule  }}'
    regexp: '{{ item.regex }}'
    create: true
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"auditd.service" in ansible_facts.services'
  - '"auditctl" in check_rules_scripts_result.stdout'
  register: auditctl_audit_rules_privilege_function_update_result
  with_items: '{{ suid_audit_rules }}'
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Restart Auditd
  ansible.builtin.command: /usr/sbin/service auditd restart
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (augenrules_audit_rules_privilege_function_update_result.changed or auditctl_audit_rules_privilege_function_update_result.changed)
  - ansible_facts.services["auditd.service"].state == "running"
  tags:
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(3)
  - NIST-800-53-AU-7(a)
  - NIST-800-53-AU-7(b)
  - NIST-800-53-AU-8(b)
  - NIST-800-53-CM-5(1)
  - audit_rules_suid_privilege_function
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	
	OTHER_FILTERS="-C uid!=euid -F euid=0"
	
	AUID_FILTERS=""
	SYSCALL="execve"
	KEY="setuid"
	SYSCALL_GROUPING=""
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

for ARCH in "${RULE_ARCHS[@]}"
do
	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
	
	OTHER_FILTERS="-C gid!=egid -F egid=0"
	
	AUID_FILTERS=""
	SYSCALL="execve"
	KEY="setgid"
	SYSCALL_GROUPING=""
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()


# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
    file_to_inspect="/etc/audit/rules.d/$KEY.rules"
    files_to_inspect=("$file_to_inspect")
    if [ ! -e "$file_to_inspect" ]
    then
        touch "$file_to_inspect"
        chmod 0640 "$file_to_inspect"
    fi
fi

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
	unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
#  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
# -----------------------------------------------------------------------------------------
#        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
# -----------------------------------------------------------------------------------------
#        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
#        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()



# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )

# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1

for audit_file in "${files_to_inspect[@]}"
do
    # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
    # i.e, collect rules that match:
    # * the action, list and arch, (2-nd argument)
    # * the other filters, (3-rd argument)
    # * the auid filters, (4-rd argument)
    readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

    candidate_rules=()
    # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
    for s_rule in "${similar_rules[@]}"
    do
        # Strip all the options and fields we know of,
        # than check if there was any field left over
        extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
        grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
    done

    if [[ ${#syscall_a[@]} -ge 1 ]]
    then
        # Check if the syscall we want is present in any of the similar existing rules
        for rule in "${candidate_rules[@]}"
        do
            rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
            all_syscalls_found=0
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                   # A syscall was not found in the candidate rule
                   all_syscalls_found=1
                   }
            done
            if [[ $all_syscalls_found -eq 0 ]]
            then
                # We found a rule with all the syscall(s) we want; skip rest of macro
                skip=0
                break
            fi

            # Check if this rule can be grouped with our target syscall and keep track of it
            for syscall_g in "${syscall_grouping[@]}"
            do
                if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                then
                    file_to_edit=${audit_file}
                    rule_to_edit=${rule}
                    rule_syscalls_to_edit=${rule_syscalls}
                fi
            done
        done
    else
        # If there is any candidate rule, it is compliant; skip rest of macro
        if [ "${#candidate_rules[@]}" -gt 0 ]
        then
            skip=0
        fi
    fi

    if [ "$skip" -eq 0 ]; then
        break
    fi
done

if [ "$skip" -ne 0 ]; then
    # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
    # At this point we know if we need to either append the $full_rule or group
    # the syscall together with an exsiting rule

    # Append the full_rule if it cannot be grouped to any other rule
    if [ -z ${rule_to_edit+x} ]
    then
        # Build full_rule while avoid adding double spaces when other_filters is empty
        if [ "${#syscall_a[@]}" -gt 0 ]
        then
            syscall_string=""
            for syscall in "${syscall_a[@]}"
            do
                syscall_string+=" -S $syscall"
            done
        fi
        other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
        auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
        full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
        echo "$full_rule" >> "$default_file"
        chmod o-rwx ${default_file}
    else
        # Check if the syscalls are declared as a comma separated list or
        # as multiple -S parameters
        if grep -q -- "," <<< "${rule_syscalls_to_edit}"
        then
            delimiter=","
        else
            delimiter=" -S "
        fi
        new_grouped_syscalls="${rule_syscalls_to_edit}"
        for syscall in "${syscall_a[@]}"
        do
            grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
               # A syscall was not found in the candidate rule
               new_grouped_syscalls+="${delimiter}${syscall}"
               }
        done

        # Group the syscall in the rule
        sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
    fi
fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure auditd Collects System Administrator Actions   [ref]

At a minimum, the audit system should collect administrator actions for all users and root. If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-w /etc/sudoers -p wa -k actions
-w /etc/sudoers.d/ -p wa -k actions
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file:
-w /etc/sudoers -p wa -k actions
-w /etc/sudoers.d/ -p wa -k actions
Rationale:
The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_sysadmin_actions
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000126, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, AC-2(7)(b), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.2, Req-10.2.5.b, 10.2.1.5, 10.2.2, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ -w%20/etc/sudoers.d/%20-p%20wa%20-k%20actions%0A-w%20/etc/sudoers%20-p%20wa%20-k%20actions%0A }}
        mode: 0600
        path: /etc/audit/rules.d/75-audit-sysadmin-actions.rules
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key actions
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)actions$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/actions.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/actions.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/sudoers -p wa -k actions
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/sudoers -p wa -k actions
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers.d/ already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key actions
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)actions$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/actions.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/actions.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers.d/ in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/sudoers.d/ -p wa -k actions
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers.d/ already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers.d/ in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/sudoers.d/ -p wa -k actions
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(7)(b)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.2
  - PCI-DSS-Req-10.2.5.b
  - PCI-DSSv4-10.2.1.5
  - PCI-DSSv4-10.2.2
  - audit_rules_sysadmin_actions
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/actions.rules"
    # If the actions.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"
    fi
done

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers.d/" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/actions.rules"
    # If the actions.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify User/Group Information - /etc/group   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d, in order to capture events that modify account changes:

-w /etc/group -p wa -k audit_rules_usergroup_modification


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file, in order to capture events that modify account changes:

-w /etc/group -p wa -k audit_rules_usergroup_modification
Rationale:
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_group
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-001405, CCI-001683, CCI-001684, CCI-001685, CCI-001686, CCI-002130, CCI-002132, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.5, 10.2.1.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/group already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/group\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
    for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/group in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/group -p wa -k audit_rules_usergroup_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/group already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/group\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/group in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/group -p wa -k audit_rules_usergroup_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_group
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/group" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/group $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/group$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/group -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/group" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
    # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/group" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/group $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/group$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/group -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify User/Group Information - /etc/gshadow   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d, in order to capture events that modify account changes:

-w /etc/gshadow -p wa -k audit_rules_usergroup_modification


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file, in order to capture events that modify account changes:

-w /etc/gshadow -p wa -k audit_rules_usergroup_modification
Rationale:
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_gshadow
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-001405, CCI-001683, CCI-001684, CCI-001685, CCI-001686, CCI-002130, CCI-002132, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.5, 10.2.1.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/gshadow already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/gshadow\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
    for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/gshadow in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/gshadow already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/gshadow\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/gshadow in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/gshadow" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/gshadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/gshadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/gshadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/gshadow" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
    # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/gshadow" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/gshadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/gshadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/gshadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify User/Group Information - /etc/security/opasswd   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d, in order to capture events that modify account changes:

-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file, in order to capture events that modify account changes:

-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
Rationale:
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_opasswd
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-001405, CCI-001683, CCI-001684, CCI-001685, CCI-001686, CCI-002130, CCI-002132, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.5, 10.2.1.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/security/opasswd already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/security/opasswd\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
    for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/security/opasswd in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/security/opasswd already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/security/opasswd\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/security/opasswd in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_opasswd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/security/opasswd" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/security/opasswd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/security/opasswd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/security/opasswd" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
    # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/security/opasswd" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/security/opasswd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/security/opasswd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify User/Group Information - /etc/passwd   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d, in order to capture events that modify account changes:

-w /etc/passwd -p wa -k audit_rules_usergroup_modification


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file, in order to capture events that modify account changes:

-w /etc/passwd -p wa -k audit_rules_usergroup_modification
Rationale:
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_passwd
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-001405, CCI-001683, CCI-001684, CCI-001685, CCI-001686, CCI-002130, CCI-002132, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.5, 10.2.1.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-OS-000274-GPOS-00104, SRG-OS-000275-GPOS-00105, SRG-OS-000276-GPOS-00106, SRG-OS-000277-GPOS-00107


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/passwd already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/passwd\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
    for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/passwd in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/passwd -p wa -k audit_rules_usergroup_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/passwd already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/passwd\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/passwd in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/passwd -p wa -k audit_rules_usergroup_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/passwd" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/passwd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/passwd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/passwd" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
    # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/passwd" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/passwd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/passwd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Events that Modify User/Group Information - /etc/shadow   [ref]

If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d, in order to capture events that modify account changes:

-w /etc/shadow -p wa -k audit_rules_usergroup_modification


If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file, in order to capture events that modify account changes:

-w /etc/shadow -p wa -k audit_rules_usergroup_modification
Rationale:
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_shadow
Identifiers and References

References:  BP28(R73), 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000018, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001403, CCI-001404, CCI-001405, CCI-001683, CCI-001684, CCI-001685, CCI-001686, CCI-002130, CCI-002132, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1.1.c, Req-10.2.5, 10.2.1.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/shadow already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/shadow\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
    for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/shadow in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/shadow -p wa -k audit_rules_usergroup_modification
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /etc/shadow already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/shadow\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /etc/shadow in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/shadow -p wa -k audit_rules_usergroup_modification
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.1.7
  - NIST-800-53-AC-2(4)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.2.5
  - PCI-DSSv4-10.2.1.5
  - audit_rules_usergroup_modification_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/shadow" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/shadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/shadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/shadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/shadow" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
    # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/shadow" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/shadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/shadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/shadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Record Attempts to perform maintenance activities   [ref]

The Fedora operating system must generate audit records for privileged activities, nonlocal maintenance, diagnostic sessions and other system-level access. Verify the operating system audits activities performed during nonlocal maintenance and diagnostic sessions. Run the following command:
$ sudo auditctl -l | grep sudo.log
-w /var/log/sudo.log -p wa -k maintenance
Rationale:
If events associated with nonlocal administrative access or diagnostic sessions are not logged, a major tool for assessing and investigating attacks would not be available. This requirement addresses auditing-related issues associated with maintenance tools used specifically for diagnostic and repair actions on organizational information systems. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. This requirement applies to hardware/software diagnostic test equipment or tools. This requirement does not cover hardware/software components that may support information system maintenance, yet are a part of the system, for example, the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_sudo_log_events
Identifiers and References

References:  CCI-000172, CCI-002884, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/log/sudo.log already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/var/log/sudo.log\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key logins
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)logins$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use /etc/audit/rules.d/logins.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/logins.rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/log/sudo.log in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /var/log/sudo.log -p wa -k logins
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check if watch rule for /var/log/sudo.log already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/var/log/sudo.log\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add watch rule for /var/log/sudo.log in /etc/audit/audit.rules
  lineinfile:
    line: -w /var/log/sudo.log -p wa -k logins
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - audit_sudo_log_events
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()


# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/log/sudo.log" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/sudo.log $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/log/sudo.log$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/log/sudo.log -p wa -k logins" >> "$audit_rules_file"
    fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
# -----------------------------------------------------------------------------------------
#	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
# -----------------------------------------------------------------------------------------
# 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
# 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
# -----------------------------------------------------------------------------------------
files_to_inspect=()

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/logins.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/sudo.log" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/logins.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/logins.rules"
    # If the logins.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/var/log/sudo.log" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/sudo.log $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/var/log/sudo.log$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /var/log/sudo.log -p wa -k logins" >> "$audit_rules_file"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Configure auditd Data Retention   Group contains 2 rules
[ref]   The audit system writes data to /var/log/audit/audit.log. By default, auditd rotates 5 logs by size (6MB), retaining a maximum of 30MB of data in total, and refuses to write entries when the disk is too full. This minimizes the risk of audit data filling its partition and impacting other services. This also minimizes the risk of the audit daemon temporarily disabling the system if it cannot write audit log (which it can be configured to do). For a busy system or a system which is thoroughly auditing system activity, the default settings for data retention may be insufficient. The log file size needed will depend heavily on what types of events are being audited. First configure auditing to log all the events of interest. Then monitor the log size manually for awhile to determine what file size will allow you to keep the required data for the correct time period.

Using a dedicated partition for /var/log/audit prevents the auditd logs from disrupting system functionality if they fill, and, more importantly, prevents other activity in /var from filling the partition and stopping the audit trail. (The audit logs are size-limited and therefore unlikely to grow without bound unless configured to do so.) Some machines may have requirements that no actions occur which cannot be audited. If this is the case, then auditd can be configured to halt the machine if it runs out of space. Note: Since older logs are rotated, configuring auditd this way does not prevent older logs from being rotated away before they can be viewed. If your system is configured to halt when logging cannot be performed, make sure this can never happen under normal circumstances! Ensure that /var/log/audit is on its own partition, and that this partition is larger than the maximum amount of data auditd will retain normally.

Rule   Configure auditd Max Log File Size   [ref]

Determine the amount of audit data (in megabytes) which should be retained in each log file. Edit the file /etc/audit/auditd.conf. Add or modify the following line, substituting the correct value of 6 for STOREMB:
max_log_file = STOREMB
Set the value to 6 (MB) or higher for general-purpose systems. Larger values, of course, support retention of even more audit data.
Rationale:
The total storage for audit log files must be large enough to retain log information over the period required. This is a function of the maximum log file size and the number of logs retained.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_data_retention_max_log_file
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, CIP-004-6 R2.2.3, CIP-004-6 R3.3, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AU-11, CM-6(a), DE.AE-3, DE.AE-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7, 10.5.1


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ %23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20%7B%7B.var_auditd_flush%7D%7D%0Afreq%20%3D%2050%0Amax_log_file%20%3D%20%7B%7B.var_auditd_max_log_file%7D%7D%0Anum_logs%20%3D%20%7B%7B.var_auditd_num_logs%7D%7D%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20%7B%7B.var_auditd_max_log_file_action%7D%7D%0Aspace_left%20%3D%20%7B%7B.var_auditd_space_left%7D%7D%0Aspace_left_action%20%3D%20%7B%7B.var_auditd_space_left_action%7D%7D%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20%7B%7B.var_auditd_action_mail_acct%7D%7D%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20syslog%0Adisk_full_action%20%3D%20%7B%7B.var_auditd_disk_full_action%7D%7D%0Adisk_error_action%20%3D%20%7B%7B.var_auditd_disk_error_action%7D%7D%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20syslog%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d }}
        mode: 0640
        path: /etc/audit/auditd.conf
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-53-AU-11
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - PCI-DSSv4-10.5.1
  - auditd_data_retention_max_log_file
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_auditd_max_log_file # promote to variable
  set_fact:
    var_auditd_max_log_file: !!str 6
  tags:
    - always

- name: Configure auditd Max Log File Size
  lineinfile:
    dest: /etc/audit/auditd.conf
    regexp: ^\s*max_log_file\s*=\s*.*$
    line: max_log_file = {{ var_auditd_max_log_file }}
    state: present
    create: true
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-53-AU-11
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - PCI-DSSv4-10.5.1
  - auditd_data_retention_max_log_file
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

var_auditd_max_log_file='6'


AUDITCONFIG=/etc/audit/auditd.conf

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^max_log_file")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_max_log_file"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^max_log_file\\>" "$AUDITCONFIG"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^max_log_file\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
    if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
    fi
    printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure auditd max_log_file_action Upon Reaching Maximum Log Size   [ref]

The default action to take when the logs reach their maximum size is to rotate the log files, discarding the oldest one. To configure the action taken by auditd, add or correct the line in /etc/audit/auditd.conf:
max_log_file_action = ACTION
Possible values for ACTION are described in the auditd.conf man page. These include:
  • ignore
  • syslog
  • suspend
  • rotate
  • keep_logs
Set the ACTION to rotate to ensure log rotation occurs. This is the default. The setting is case-insensitive.
Rationale:
Automatically rotating logs (by setting this to rotate) minimizes the chances of the system unexpectedly running out of disk space by being overwhelmed with log data. However, for systems that must never discard log data, or which use external processes to transfer it and reclaim space, keep_logs can be employed.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_auditd_data_retention_max_log_file_action
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, CCI-000140, 164.312(a)(2)(ii), 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1, AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a), DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7, 10.5.1, SRG-OS-000047-GPOS-00023


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ %23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20audit%20daemon%0A%23%0A%0Alocal_events%20%3D%20yes%0Awrite_logs%20%3D%20yes%0Alog_file%20%3D%20/var/log/audit/audit.log%0Alog_group%20%3D%20root%0Alog_format%20%3D%20ENRICHED%0Aflush%20%3D%20%7B%7B.var_auditd_flush%7D%7D%0Afreq%20%3D%2050%0Amax_log_file%20%3D%20%7B%7B.var_auditd_max_log_file%7D%7D%0Anum_logs%20%3D%20%7B%7B.var_auditd_num_logs%7D%7D%0Apriority_boost%20%3D%204%0Aname_format%20%3D%20hostname%0A%23%23name%20%3D%20mydomain%0Amax_log_file_action%20%3D%20%7B%7B.var_auditd_max_log_file_action%7D%7D%0Aspace_left%20%3D%20%7B%7B.var_auditd_space_left%7D%7D%0Aspace_left_action%20%3D%20%7B%7B.var_auditd_space_left_action%7D%7D%0Averify_email%20%3D%20yes%0Aaction_mail_acct%20%3D%20%7B%7B.var_auditd_action_mail_acct%7D%7D%0Aadmin_space_left%20%3D%2050%0Aadmin_space_left_action%20%3D%20syslog%0Adisk_full_action%20%3D%20%7B%7B.var_auditd_disk_full_action%7D%7D%0Adisk_error_action%20%3D%20%7B%7B.var_auditd_disk_error_action%7D%7D%0Ause_libwrap%20%3D%20yes%0A%23%23tcp_listen_port%20%3D%2060%0Atcp_listen_queue%20%3D%205%0Atcp_max_per_addr%20%3D%201%0A%23%23tcp_client_ports%20%3D%201024-65535%0Atcp_client_max_idle%20%3D%200%0Atransport%20%3D%20TCP%0Akrb5_principal%20%3D%20auditd%0A%23%23krb5_key_file%20%3D%20/etc/audit/audit.key%0Adistribute_network%20%3D%20no%0Aq_depth%20%3D%20400%0Aoverflow_action%20%3D%20syslog%0Amax_restarts%20%3D%2010%0Aplugin_dir%20%3D%20/etc/audit/plugins.d }}
        mode: 0640
        path: /etc/audit/auditd.conf
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-53-AU-5(1)
  - NIST-800-53-AU-5(2)
  - NIST-800-53-AU-5(4)
  - NIST-800-53-AU-5(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - PCI-DSSv4-10.5.1
  - auditd_data_retention_max_log_file_action
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_auditd_max_log_file_action # promote to variable
  set_fact:
    var_auditd_max_log_file_action: !!str rotate
  tags:
    - always

- name: Configure auditd max_log_file_action Upon Reaching Maximum Log Size
  lineinfile:
    dest: /etc/audit/auditd.conf
    line: max_log_file_action = {{ var_auditd_max_log_file_action }}
    regexp: ^\s*max_log_file_action\s*=\s*.*$
    state: present
    create: true
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.4.1.1
  - NIST-800-53-AU-5(1)
  - NIST-800-53-AU-5(2)
  - NIST-800-53-AU-5(4)
  - NIST-800-53-AU-5(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - PCI-DSSv4-10.5.1
  - auditd_data_retention_max_log_file_action
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; then

var_auditd_max_log_file_action='rotate'


AUDITCONFIG=/etc/audit/auditd.conf

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^max_log_file_action")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_max_log_file_action"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^max_log_file_action\\>" "$AUDITCONFIG"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^max_log_file_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
    if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
    fi
    printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure the audit Subsystem is Installed   [ref]

The audit package should be installed.
Rationale:
The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_audit_installed
Identifiers and References

References:  BP28(R50), CCI-000130, CCI-000131, CCI-000132, CCI-000133, CCI-000134, CCI-000135, CCI-000154, CCI-000158, CCI-000172, CCI-001464, CCI-001487, CCI-001814, CCI-001875, CCI-001876, CCI-001877, CCI-001878, CCI-001879, CCI-001880, CCI-001881, CCI-001882, CCI-001889, CCI-001914, CCI-002884, CCI-000169, CIP-004-6 R3.3, CIP-007-3 R6.5, AC-7(a), AU-7(1), AU-7(2), AU-14, AU-12(2), AU-2(a), CM-6(a), FAU_GEN.1, Req-10.1, 10.2.1, SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220


Complexity:low
Disruption:low
Strategy:enable

package --add=audit


[[packages]]
name = "audit"
version = "*"

Complexity:low
Disruption:low
Strategy:enable
include install_audit

class install_audit {
  package { 'audit':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure audit is installed
  package:
    name: audit
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-7(a)
  - NIST-800-53-AU-12(2)
  - NIST-800-53-AU-14
  - NIST-800-53-AU-2(a)
  - NIST-800-53-AU-7(1)
  - NIST-800-53-AU-7(2)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_audit_installed

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if ! rpm -q --quiet "audit" ; then
    dnf install -y "audit"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable auditd Service   [ref]

The auditd service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The auditd service can be enabled with the following command:
$ sudo systemctl enable auditd.service
Rationale:
Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the auditd service is active ensures audit records generated by the kernel are appropriately recorded.

Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_auditd_enabled
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 3.3.2, 3.3.6, CCI-000126, CCI-000130, CCI-000131, CCI-000132, CCI-000133, CCI-000134, CCI-000135, CCI-000154, CCI-000158, CCI-000172, CCI-000366, CCI-001464, CCI-001487, CCI-001814, CCI-001875, CCI-001876, CCI-001877, CCI-002884, CCI-001878, CCI-001879, CCI-001880, CCI-001881, CCI-001882, CCI-001889, CCI-001914, CCI-000169, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, CIP-004-6 R3.3, CIP-007-3 R6.5, AC-2(g), AU-3, AU-10, AU-2(d), AU-12(c), AU-14(1), AC-6(9), CM-6(a), SI-4(23), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1, Req-10.1, 10.2.1, SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
      - name: auditd.service
        enabled: true


[customizations.services]
enabled = ["auditd"]

Complexity:low
Disruption:low
Strategy:enable
include enable_auditd

class enable_auditd {
  service {'auditd':
    enable => true,
    ensure => 'running',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.3.2
  - NIST-800-171-3.3.6
  - NIST-800-53-AC-2(g)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-10
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-14(1)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-AU-3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-4(23)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_auditd_enabled

- name: Enable service auditd
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service auditd
    systemd:
      name: auditd
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"audit" in ansible_facts.packages'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"audit" in ansible_facts.packages'
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.3.2
  - NIST-800-171-3.3.6
  - NIST-800-53-AC-2(g)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-10
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-14(1)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-AU-3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-4(23)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_auditd_enabled

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q audit; }; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'auditd.service'
"$SYSTEMCTL_EXEC" start 'auditd.service'
"$SYSTEMCTL_EXEC" enable 'auditd.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Auditing for Processes Which Start Prior to the Audit Daemon   [ref]

To ensure all processes can be audited, even those which start prior to the audit daemon, add the argument audit=1 to the default GRUB 2 command line for the Linux operating system. Configure the default Grub2 kernel command line to contain audit=1 as follows:
# grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit=1"
Rationale:
Each process on the system carries an "auditable" flag which indicates whether its activities can be audited. Although auditd takes care of enabling this for all processes which launch after it does, adding the kernel argument ensures it is set for every process during boot.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_grub2_audit_argument
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.02, DSS05.03, DSS05.04, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, CCI-001464, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AC-17(1), AU-14(1), AU-10, CM-6(a), IR-5(1), DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1, Req-10.3, 10.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000254-GPOS-00095


[customizations.kernel]
append = "audit=1"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-53-AC-17(1)
  - NIST-800-53-AU-10
  - NIST-800-53-AU-14(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IR-5(1)
  - PCI-DSS-Req-10.3
  - PCI-DSSv4-10.7
  - grub2_audit_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="audit=1"
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-53-AC-17(1)
  - NIST-800-53-AU-10
  - NIST-800-53-AU-14(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IR-5(1)
  - PCI-DSS-Req-10.3
  - PCI-DSSv4-10.7
  - grub2_audit_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q grub2-common; }; then

grubby --update-kernel=ALL --args=audit=1

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Extend Audit Backlog Limit for the Audit Daemon   [ref]

To improve the kernel capacity to queue all log events, even those which occurred prior to the audit daemon, add the argument audit_backlog_limit=8192 to the default GRUB 2 command line for the Linux operating system. Configure the default Grub2 kernel command line to contain audit_backlog_limit=8192 as follows:
# grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit_backlog_limit=8192"
Rationale:
audit_backlog_limit sets the queue length for audit events awaiting transfer to the audit daemon. Until the audit daemon is up and running, all log messages are stored in this queue. If the queue is overrun during boot process, the action defined by audit failure flag is taken.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_grub2_audit_backlog_limit_argument
Identifiers and References

References:  CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-001849, CCI-002884, CM-6(a), FAU_STG.1, FAU_STG.3, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000254-GPOS-00095, SRG-OS-000341-GPOS-00132, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215


[customizations.kernel]
append = "audit_backlog_limit=8192"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_audit_backlog_limit_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="audit_backlog_limit=8192"
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_audit_backlog_limit_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q grub2-common; }; then

grubby --update-kernel=ALL --args=audit_backlog_limit=8192

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   GRUB2 bootloader configuration   Group contains 2 groups and 14 rules
[ref]   During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows for the selection of different kernels - possibly on different partitions or media. The default Fedora boot loader for x86 systems is called GRUB2. Options it can pass to the kernel include single-user mode, which provides root access without any authentication, and the ability to disable SELinux. To prevent local users from modifying the boot parameters and endangering security, protect the boot loader configuration with a password and ensure its configuration file's permissions are set properly.
Group   Non-UEFI GRUB2 bootloader configuration   Group contains 7 rules
[ref]   Non-UEFI GRUB2 bootloader configuration

Rule   Verify /boot/grub2/grub.cfg Group Ownership   [ref]

The file /boot/grub2/grub.cfg should be group-owned by the root group to prevent destruction or modification of the file. To properly set the group owner of /boot/grub2/grub.cfg, run the command:
$ sudo chgrp root /boot/grub2/grub.cfg
Rationale:
The root group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_grub2_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    group: '0'
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chgrp 0 /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/user.cfg Group Ownership   [ref]

The file /boot/grub2/user.cfg should be group-owned by the root group to prevent reading or modification of the file. To properly set the group owner of /boot/grub2/user.cfg, run the command:
$ sudo chgrp root /boot/grub2/user.cfg
Rationale:
The root group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway. Non-root users who read the boot parameters may be able to identify weaknesses in security upon boot and be able to exploit them.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_user_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/user.cfg
  stat:
    path: /boot/grub2/user.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /boot/grub2/user.cfg
  file:
    path: /boot/grub2/user.cfg
    group: '0'
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chgrp 0 /boot/grub2/user.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/grub.cfg User Ownership   [ref]

The file /boot/grub2/grub.cfg should be owned by the root user to prevent destruction or modification of the file. To properly set the owner of /boot/grub2/grub.cfg, run the command:
$ sudo chown root /boot/grub2/grub.cfg 
Rationale:
Only root should be able to modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_grub2_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, 2.2.6


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    owner: '0'
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chown 0 /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/user.cfg User Ownership   [ref]

The file /boot/grub2/user.cfg should be owned by the root user to prevent reading or modification of the file. To properly set the owner of /boot/grub2/user.cfg, run the command:
$ sudo chown root /boot/grub2/user.cfg 
Rationale:
Only root should be able to modify important boot parameters. Also, non-root users who read the boot parameters may be able to identify weaknesses in security upon boot and be able to exploit them.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_user_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/user.cfg
  stat:
    path: /boot/grub2/user.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /boot/grub2/user.cfg
  file:
    path: /boot/grub2/user.cfg
    owner: '0'
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chown 0 /boot/grub2/user.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/grub.cfg Permissions   [ref]

File permissions for /boot/grub2/grub.cfg should be set to 600. To properly set the permissions of /boot/grub2/grub.cfg, run the command:
$ sudo chmod 600 /boot/grub2/grub.cfg
Rationale:
Proper permissions ensure that only the root user can modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chmod u-xs,g-xwrs,o-xwrt /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/user.cfg Permissions   [ref]

File permissions for /boot/grub2/user.cfg should be set to 600. To properly set the permissions of /boot/grub2/user.cfg, run the command:
$ sudo chmod 600 /boot/grub2/user.cfg
Rationale:
Proper permissions ensure that only the root user can read or modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_user_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/user.cfg
  stat:
    path: /boot/grub2/user.cfg
  register: file_exists
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/user.cfg
  file:
    path: /boot/grub2/user.cfg
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - '"/boot/efi" not in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chmod u-xs,g-xwrs,o-xwrt /boot/grub2/user.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set Boot Loader Password in grub2   [ref]

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the password by running the following command:
# grub2-setpassword
When prompted, enter the password that was selected.

Warning:  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Rationale:
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_password
Identifiers and References

References:  BP28(R17), 1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048

Group   UEFI GRUB2 bootloader configuration   Group contains 7 rules
[ref]   UEFI GRUB2 bootloader configuration

Rule   Verify the UEFI Boot Loader grub.cfg Group Ownership   [ref]

The file /boot/grub2/grub.cfg should be group-owned by the root group to prevent destruction or modification of the file. To properly set the group owner of /boot/grub2/grub.cfg, run the command:
$ sudo chgrp root /boot/grub2/grub.cfg
Rationale:
The root group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_efi_grub2_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    group: '0'
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chgrp 0 /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/user.cfg Group Ownership   [ref]

The file /boot/grub2/user.cfg should be group-owned by the root group to prevent reading or modification of the file. To properly set the group owner of /boot/grub2/user.cfg, run the command:
$ sudo chgrp root /boot/grub2/user.cfg
Rationale:
The root group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway. Non-root users who read the boot parameters may be able to identify weaknesses in security upon boot and be able to exploit them.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_efi_user_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/user.cfg
  stat:
    path: /boot/grub2/user.cfg
  register: file_exists
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /boot/grub2/user.cfg
  file:
    path: /boot/grub2/user.cfg
    group: '0'
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_groupowner_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chgrp 0 /boot/grub2/user.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify the UEFI Boot Loader grub.cfg User Ownership   [ref]

The file /boot/grub2/grub.cfg should be owned by the root user to prevent destruction or modification of the file. To properly set the owner of /boot/grub2/grub.cfg, run the command:
$ sudo chown root /boot/grub2/grub.cfg 
Rationale:
Only root should be able to modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_efi_grub2_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    owner: '0'
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chown 0 /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/user.cfg User Ownership   [ref]

The file /boot/grub2/user.cfg should be owned by the root user to prevent reading or modification of the file. To properly set the owner of /boot/grub2/user.cfg, run the command:
$ sudo chown root /boot/grub2/user.cfg 
Rationale:
Only root should be able to modify important boot parameters. Also, non-root users who read the boot parameters may be able to identify weaknesses in security upon boot and be able to exploit them.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_efi_user_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/user.cfg
  stat:
    path: /boot/grub2/user.cfg
  register: file_exists
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /boot/grub2/user.cfg
  file:
    path: /boot/grub2/user.cfg
    owner: '0'
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-7.1
  - configure_strategy
  - file_owner_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chown 0 /boot/grub2/user.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify the UEFI Boot Loader grub.cfg Permissions   [ref]

File permissions for /boot/grub2/grub.cfg should be set to 700. To properly set the permissions of /boot/grub2/grub.cfg, run the command:
$ sudo chmod 700 /boot/grub2/grub.cfg
Rationale:
Proper permissions ensure that only the root user can modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_efi_grub2_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/grub.cfg
  stat:
    path: /boot/grub2/grub.cfg
  register: file_exists
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-s,g-xwrs,o-xwrt on /boot/grub2/grub.cfg
  file:
    path: /boot/grub2/grub.cfg
    mode: u-s,g-xwrs,o-xwrt
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_efi_grub2_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chmod u-s,g-xwrs,o-xwrt /boot/grub2/grub.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify /boot/grub2/user.cfg Permissions   [ref]

File permissions for /boot/grub2/user.cfg should be set to 600. To properly set the permissions of /boot/grub2/user.cfg, run the command:
$ sudo chmod 600 /boot/grub2/user.cfg
Rationale:
Proper permissions ensure that only the root user can read or modify important boot parameters.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_efi_user_cfg
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /boot/grub2/user.cfg
  stat:
    path: /boot/grub2/user.cfg
  register: file_exists
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/user.cfg
  file:
    path: /boot/grub2/user.cfg
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - '"/boot/efi" in ansible_mounts | map(attribute="mount") | list'
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-171-3.4.5
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_efi_user_cfg
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ -d /sys/firmware/efi ] && rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

chmod u-xs,g-xwrs,o-xwrt /boot/grub2/user.cfg

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set the UEFI Boot Loader Password   [ref]

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the password by running the following command:
# grub2-setpassword
When prompted, enter the password that was selected.

Warning:  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Rationale:
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_uefi_password
Identifiers and References

References:  BP28(R17), 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048

Group   Configure Syslog   Group contains 1 group and 4 rules
[ref]   The syslog service has been the default Unix logging mechanism for many years. It has a number of downsides, including inconsistent log format, lack of authentication for received messages, and lack of authentication, encryption, or reliable transport for messages sent over a network. However, due to its long history, syslog is a de facto standard which is supported by almost all Unix applications.

In Fedora, rsyslog has replaced ksyslogd as the syslog daemon of choice, and it includes some additional security features such as reliable, connection-oriented (i.e. TCP) transmission of logs, the option to log to database formats, and the encryption of log data en route to a central logging server. This section discusses how to configure rsyslog for best effect, and how to use tools provided with the system to maintain and monitor logs.
Group   systemd-journald   Group contains 4 rules
[ref]   systemd-journald is a system service that collects and stores logging data. It creates and maintains structured, indexed journals based on logging information that is received from a variety of sources. For more information on systemd-journald and additional systemd-journald configuration options, see https://systemd.io/.

Rule   Enable systemd-journald Service   [ref]

The systemd-journald service is an essential component of systemd. The systemd-journald service can be enabled with the following command:
$ sudo systemctl enable systemd-journald.service
Rationale:
In the event of a system failure, Fedora must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to system processes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_systemd-journald_enabled
Identifiers and References

References:  CCI-001665, SC-24, SRG-OS-000269-GPOS-00103



[customizations.services]
enabled = ["systemd-journald"]

Complexity:low
Disruption:low
Strategy:enable
include enable_systemd-journald

class enable_systemd-journald {
  service {'systemd-journald':
    enable => true,
    ensure => 'running',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Enable service systemd-journald
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service systemd-journald
    systemd:
      name: systemd-journald
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"systemd" in ansible_facts.packages'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SC-24
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_systemd-journald_enabled

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'systemd-journald.service'
"$SYSTEMCTL_EXEC" start 'systemd-journald.service'
"$SYSTEMCTL_EXEC" enable 'systemd-journald.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure journald is configured to compress large log files   [ref]

The journald system can compress large log files to avoid fill the system disk.
Rationale:
Log files that are not properly compressed run the risk of growing so large that they fill up the log partition. Valuable logging information could be lost if the log partition becomes full.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_journald_compress
Identifiers and References

Complexity:low
Disruption:low
Strategy:restrict
- name: Setting shell-quoted shell-style assignment of 'Compress' to 'yes' in '/etc/systemd/journald.conf'
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/systemd/journald.conf
      create: false
      regexp: ^\s*Compress=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/systemd/journald.conf
    lineinfile:
      path: /etc/systemd/journald.conf
      create: false
      regexp: ^\s*Compress=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/systemd/journald.conf
    lineinfile:
      path: /etc/systemd/journald.conf
      create: true
      regexp: ^\s*Compress=
      line: Compress="yes"
      state: present
      insertbefore: ^# Compress
      validate: /usr/bin/bash -n %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - journald_compress
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/systemd/journald.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*Compress\s*=\s*/d" "/etc/systemd/journald.conf"
else
    touch "/etc/systemd/journald.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/journald.conf"

cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
# Insert before the line matching the regex '^#\s*Compress'.
line_number="$(LC_ALL=C grep -n "^#\s*Compress" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^#\s*Compress', insert at
    # the end of the file.
    printf '%s\n' "Compress='yes'" >> "/etc/systemd/journald.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
    printf '%s\n' "Compress='yes'" >> "/etc/systemd/journald.conf"
    tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
fi
# Clean up after ourselves.
rm "/etc/systemd/journald.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure journald is configured to write log files to persistent disk   [ref]

The journald system may store log files in volatile memory or locally on disk. If the logs are only stored in volatile memory they will we lost upon reboot.
Rationale:
Log files contain valuable data and need to be persistent to aid in possible investigations.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_journald_storage
Identifiers and References

Complexity:low
Disruption:low
Strategy:restrict
- name: Setting shell-quoted shell-style assignment of 'Storage' to 'persistent' in
    '/etc/systemd/journald.conf'
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/systemd/journald.conf
      create: false
      regexp: ^\s*Storage=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/systemd/journald.conf
    lineinfile:
      path: /etc/systemd/journald.conf
      create: false
      regexp: ^\s*Storage=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/systemd/journald.conf
    lineinfile:
      path: /etc/systemd/journald.conf
      create: true
      regexp: ^\s*Storage=
      line: Storage="persistent"
      state: present
      insertbefore: ^# Storage
      validate: /usr/bin/bash -n %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - journald_storage
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/systemd/journald.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*Storage\s*=\s*/d" "/etc/systemd/journald.conf"
else
    touch "/etc/systemd/journald.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/journald.conf"

cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
# Insert before the line matching the regex '^#\s*Storage'.
line_number="$(LC_ALL=C grep -n "^#\s*Storage" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^#\s*Storage', insert at
    # the end of the file.
    printf '%s\n' "Storage='persistent'" >> "/etc/systemd/journald.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
    printf '%s\n' "Storage='persistent'" >> "/etc/systemd/journald.conf"
    tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
fi
# Clean up after ourselves.
rm "/etc/systemd/journald.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable systemd-journal-remote Socket   [ref]

Journald supports the ability to receive messages from remote hosts, thus acting as a log server. Clients should not receive data from other hosts. NOTE: The same package, systemd-journal-remote , is used for both sending logs to remote hosts and receiving incoming logs. With regards to receiving logs, there are two Systemd unit files; systemd-journal-remote.socket and systemd-journal-remote.service.
Rationale:
If a client is configured to also receive data, thus turning it into a server, the client system is acting outside it's operational boundary.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_socket_systemd-journal-remote_disabled
Identifiers and References

Complexity:low
Disruption:low
Strategy:disable
- name: Disable systemd-journal-remote Socket - Collect systemd Socket Units Present
    in the System
  ansible.builtin.command:
    cmd: systemctl -q list-unit-files --type socket
  register: result_systemd_unit_files
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - socket_systemd-journal-remote_disabled

- name: Disable systemd-journal-remote Socket - Ensure systemd-journal-remote.socket
    is Masked
  ansible.builtin.systemd:
    name: systemd-journal-remote.socket
    state: stopped
    enabled: false
    masked: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - result_systemd_unit_files.stdout_lines is search("systemd-journal-remote.socket")
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - socket_systemd-journal-remote_disabled

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SOCKET_NAME="systemd-journal-remote.socket"
SYSTEMCTL_EXEC='/usr/bin/systemctl'

if "$SYSTEMCTL_EXEC" -q list-unit-files --type socket | grep -q "$SOCKET_NAME"; then
    "$SYSTEMCTL_EXEC" stop "$SOCKET_NAME"
    "$SYSTEMCTL_EXEC" unmask "$SOCKET_NAME"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Configuration and Firewalls   Group contains 9 groups and 24 rules
[ref]   Most systems must be connected to a network of some sort, and this brings with it the substantial risk of network attack. This section discusses the security impact of decisions about networking which must be made when configuring a system.

This section also discusses firewalls, network access controls, and other network security frameworks, which allow system-level rules to be written that can limit an attackers' ability to connect to your system. These rules can specify that network traffic should be allowed or denied from certain IP addresses, hosts, and networks. The rules can also specify which of the system's network services are available to particular hosts or networks.
Group   firewalld   Group contains 1 group and 2 rules
[ref]   The dynamic firewall daemon firewalld provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly.
A graphical configuration tool, firewall-config, is used to configure firewalld, which in turn uses iptables tool to communicate with Netfilter in the kernel which implements packet filtering.
The firewall service provided by firewalld is dynamic rather than static because changes to the configuration can be made at anytime and are immediately implemented. There is no need to save or apply the changes. No unintended disruption of existing network connections occurs as no part of the firewall has to be reloaded.
Group   Inspect and Activate Default firewalld Rules   Group contains 2 rules
[ref]   Firewalls can be used to separate networks into different zones based on the level of trust the user has decided to place on the devices and traffic within that network. NetworkManager informs firewalld to which zone an interface belongs. An interface's assigned zone can be changed by NetworkManager or via the firewall-config tool.
The zone settings in /etc/firewalld/ are a range of preset settings which can be quickly applied to a network interface. These are the zones provided by firewalld sorted according to the default trust level of the zones from untrusted to trusted:
  • drop

    Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.

  • block

    Any incoming network connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6. Only network connections initiated from within the system are possible.

  • public

    For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

  • external

    For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

  • dmz

    For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.

  • work

    For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

  • home

    For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

  • internal

    For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.

  • trusted

    All network connections are accepted.


It is possible to designate one of these zones to be the default zone. When interface connections are added to NetworkManager, they are assigned to the default zone. On installation, the default zone in firewalld is set to be the public zone.
To find out all the settings of a zone, for example the public zone, enter the following command as root:
# firewall-cmd --zone=public --list-all
Example output of this command might look like the following:
# firewall-cmd --zone=public --list-all
public
  interfaces:
  services: mdns dhcpv6-client ssh
  ports:
  forward-ports:
  icmp-blocks: source-quench
To view the network zones currently active, enter the following command as root:
# firewall-cmd --get-service
The following listing displays the result of this command on common Fedora system:
# firewall-cmd --get-service
amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
samba samba-client smtp ssh telnet tftp tftp-client transmission-client
vnc-server wbem-https
Finally to view the network zones that will be active after the next firewalld service reload, enter the following command as root:
# firewall-cmd --get-service --permanent

Rule   Install firewalld Package   [ref]

The firewalld package can be installed with the following command:
$ sudo dnf install firewalld
Rationale:
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Fedora functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets)."
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_firewalld_installed
Identifiers and References

References:  CCI-002314, CM-6(a), FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000298-GPOS-00116, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00232


Complexity:low
Disruption:low
Strategy:enable

package --add=firewalld


[[packages]]
name = "firewalld"
version = "*"

Complexity:low
Disruption:low
Strategy:enable
include install_firewalld

class install_firewalld {
  package { 'firewalld':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure firewalld is installed
  package:
    name: firewalld
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_firewalld_installed

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if ! rpm -q --quiet "firewalld" ; then
    dnf install -y "firewalld"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify firewalld Enabled   [ref]

The firewalld service can be enabled with the following command:
$ sudo systemctl enable firewalld.service
Rationale:
Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_firewalld_enabled
Identifiers and References

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.3, 3.4.7, CCI-000366, CCI-000382, CCI-002314, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3, AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a), PR.IP-1, FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232



[customizations.services]
enabled = ["firewalld"]

Complexity:low
Disruption:low
Strategy:enable
include enable_firewalld

class enable_firewalld {
  service {'firewalld':
    enable => true,
    ensure => 'running',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Enable service firewalld
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service firewalld
    systemd:
      name: firewalld
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"firewalld" in ansible_facts.packages'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.3
  - NIST-800-171-3.4.7
  - NIST-800-53-AC-4
  - NIST-800-53-CA-3(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(21)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_firewalld_enabled

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'firewalld.service'
"$SYSTEMCTL_EXEC" start 'firewalld.service'
"$SYSTEMCTL_EXEC" enable 'firewalld.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   IPv6   Group contains 1 group and 4 rules
[ref]   The system includes support for Internet Protocol version 6. A major and often-mentioned improvement over IPv4 is its enormous increase in the number of available addresses. Another important feature is its support for automatic configuration of many network settings.
Group   Configure IPv6 Settings if Necessary   Group contains 4 rules
[ref]   A major feature of IPv6 is the extent to which systems implementing it can automatically configure their networking devices using information from the network. From a security perspective, manually configuring important configuration information is preferable to accepting it from the network in an unauthenticated fashion.

Rule   Disable Accepting ICMP Redirects for All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_redirects = 0
Rationale:
An illicit ICMP redirect message could result in a man-in-the-middle attack.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_redirects
Identifiers and References

References:  BP28(R22), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.all.accept_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_all_accept_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_redirects

- name: Comment out any occurrences of net.ipv6.conf.all.accept_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_redirects
    replace: '#net.ipv6.conf.all.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_redirects
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_redirects is set
  sysctl:
    name: net.ipv6.conf.all.accept_redirects
    value: '{{ sysctl_net_ipv6_conf_all_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv6.conf.all.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_redirects_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_redirects="$sysctl_net_ipv6_conf_all_accept_redirects_value"

#
# If net.ipv6.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_source_route kernel parameter, run the following command:
$ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.all.accept_source_route%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_all_accept_source_route.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_source_route

- name: Comment out any occurrences of net.ipv6.conf.all.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_source_route
    replace: '#net.ipv6.conf.all.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.all.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_all_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_source_route

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv6.conf.all.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_source_route_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_source_route="$sysctl_net_ipv6_conf_all_accept_source_route_value"

#
# If net.ipv6.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_redirects = 0
Rationale:
An illicit ICMP redirect message could result in a man-in-the-middle attack.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_redirects
Identifiers and References

References:  BP28(R22), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.default.accept_redirects%20%3D%200%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_default_accept_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_redirects

- name: Comment out any occurrences of net.ipv6.conf.default.accept_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_redirects
    replace: '#net.ipv6.conf.default.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv6.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv6_conf_default_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv6.conf.default.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_redirects_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_redirects="$sysctl_net_ipv6_conf_default_accept_redirects_value"

#
# If net.ipv6.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command:
$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv6.conf.default.accept_source_route%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv6_conf_default_accept_source_route.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route

- name: Comment out any occurrences of net.ipv6.conf.default.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_source_route
    replace: '#net.ipv6.conf.default.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_default_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv6.conf.default.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_source_route_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_source_route="$sysctl_net_ipv6_conf_default_accept_source_route_value"

#
# If net.ipv6.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Kernel Parameters Which Affect Networking   Group contains 2 groups and 15 rules
[ref]   The sysctl utility is used to set parameters which affect the operation of the Linux kernel. Kernel parameters which affect networking and have security implications are described here.
Group   Network Related Kernel Runtime Parameters for Hosts and Routers   Group contains 13 rules
[ref]   Certain kernel parameters should be set for systems which are acting as either hosts or routers to improve the system's ability defend against certain types of IPv4 protocol attacks.

Rule   Disable Accepting ICMP Redirects for All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.accept_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required."
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, 5.10.1.1, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000366, CCI-001503, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.accept_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_accept_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.accept_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.accept_redirects
    replace: '#net.ipv4.conf.all.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.all.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_all_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.all.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_accept_redirects_value='0'


#
# Set runtime for net.ipv4.conf.all.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_redirects="$sysctl_net_ipv4_conf_all_accept_redirects_value"

#
# If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.accept_source_route%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_accept_source_route.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_source_route

- name: Comment out any occurrences of net.ipv4.conf.all.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.accept_source_route
    replace: '#net.ipv4.conf.all.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_source_route
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.accept_source_route is set
  sysctl:
    name: net.ipv4.conf.all.accept_source_route
    value: '{{ sysctl_net_ipv4_conf_all_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_source_route

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.all.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_accept_source_route_value='0'


#
# Set runtime for net.ipv4.conf.all.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_source_route="$sysctl_net_ipv4_conf_all_accept_source_route_value"

#
# If net.ipv4.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.log_martians kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.log_martians = 1
Rationale:
The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_log_martians
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000126, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.log_martians%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_log_martians.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.log_martians.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(3)(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_conf_all_log_martians
  - unknown_severity

- name: Comment out any occurrences of net.ipv4.conf.all.log_martians from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.log_martians
    replace: '#net.ipv4.conf.all.log_martians'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(3)(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_conf_all_log_martians
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv4_conf_all_log_martians_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_log_martians_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.log_martians is set
  sysctl:
    name: net.ipv4.conf.all.log_martians
    value: '{{ sysctl_net_ipv4_conf_all_log_martians_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(3)(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_conf_all_log_martians
  - unknown_severity

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.all.log_martians from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.log_martians.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.log_martians" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_log_martians_value='1'


#
# Set runtime for net.ipv4.conf.all.log_martians
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.log_martians="$sysctl_net_ipv4_conf_all_log_martians_value"

#
# If net.ipv4.conf.all.log_martians present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.log_martians = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.log_martians")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_log_martians_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.log_martians\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.log_martians\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.rp_filter = 1
Rationale:
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.rp_filter%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_rp_filter.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.rp_filter.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter

- name: Comment out any occurrences of net.ipv4.conf.all.rp_filter from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.rp_filter
    replace: '#net.ipv4.conf.all.rp_filter'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_all_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.rp_filter is set
  sysctl:
    name: net.ipv4.conf.all.rp_filter
    value: '{{ sysctl_net_ipv4_conf_all_rp_filter_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.all.rp_filter from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.rp_filter.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.rp_filter" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_rp_filter_value='1'


#
# Set runtime for net.ipv4.conf.all.rp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.rp_filter="$sysctl_net_ipv4_conf_all_rp_filter_value"

#
# If net.ipv4.conf.all.rp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.rp_filter = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.rp_filter")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_rp_filter_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.rp_filter\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.rp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.secure_redirects = 0
Rationale:
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001503, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.secure_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_secure_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.secure_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.secure_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.secure_redirects
    replace: '#net.ipv4.conf.all.secure_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.all.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_all_secure_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.all.secure_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.secure_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.secure_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_secure_redirects_value='0'


#
# Set runtime for net.ipv4.conf.all.secure_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.secure_redirects="$sysctl_net_ipv4_conf_all_secure_redirects_value"

#
# If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.secure_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.secure_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_secure_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.accept_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_accept_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.accept_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.accept_redirects
    replace: '#net.ipv4.conf.default.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_default_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.default.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_accept_redirects_value='0'


#
# Set runtime for net.ipv4.conf.default.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_redirects="$sysctl_net_ipv4_conf_default_accept_redirects_value"

#
# If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures.
Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.accept_source_route%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_accept_source_route.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_source_route

- name: Comment out any occurrences of net.ipv4.conf.default.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.accept_source_route
    replace: '#net.ipv4.conf.default.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv4.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv4_conf_default_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_source_route

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.default.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_accept_source_route_value='0'


#
# Set runtime for net.ipv4.conf.default.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_source_route="$sysctl_net_ipv4_conf_default_accept_source_route_value"

#
# If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Paremeter to Log Martian Packets on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.log_martians kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.log_martians = 1
Rationale:
The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_log_martians
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000126, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.log_martians%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_log_martians.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.log_martians.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(3)(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_conf_default_log_martians
  - unknown_severity

- name: Comment out any occurrences of net.ipv4.conf.default.log_martians from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.log_martians
    replace: '#net.ipv4.conf.default.log_martians'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(3)(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_conf_default_log_martians
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv4_conf_default_log_martians_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_log_martians_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.log_martians is set
  sysctl:
    name: net.ipv4.conf.default.log_martians
    value: '{{ sysctl_net_ipv4_conf_default_log_martians_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(3)(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_conf_default_log_martians
  - unknown_severity

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.default.log_martians from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.log_martians.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.log_martians" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_log_martians_value='1'


#
# Set runtime for net.ipv4.conf.default.log_martians
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.log_martians="$sysctl_net_ipv4_conf_default_log_martians_value"

#
# If net.ipv4.conf.default.log_martians present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.log_martians = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.log_martians")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_log_martians_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.log_martians\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.log_martians\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.rp_filter kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.rp_filter = 1
Rationale:
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_rp_filter
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.rp_filter%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_rp_filter.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.rp_filter.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_rp_filter

- name: Comment out any occurrences of net.ipv4.conf.default.rp_filter from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.rp_filter
    replace: '#net.ipv4.conf.default.rp_filter'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_default_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.rp_filter is set
  sysctl:
    name: net.ipv4.conf.default.rp_filter
    value: '{{ sysctl_net_ipv4_conf_default_rp_filter_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_rp_filter

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.default.rp_filter from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.rp_filter.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.rp_filter" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_rp_filter_value='1'


#
# Set runtime for net.ipv4.conf.default.rp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.rp_filter="$sysctl_net_ipv4_conf_default_rp_filter_value"

#
# If net.ipv4.conf.default.rp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.rp_filter = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.rp_filter")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_rp_filter_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.rp_filter\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.rp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure Kernel Parameter for Accepting Secure Redirects By Default   [ref]

To set the runtime status of the net.ipv4.conf.default.secure_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.secure_redirects = 0
Rationale:
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_secure_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.secure_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_secure_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.secure_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_secure_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.secure_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.secure_redirects
    replace: '#net.ipv4.conf.default.secure_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.default.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_default_secure_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_secure_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.default.secure_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.secure_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.secure_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_secure_redirects_value='0'


#
# Set runtime for net.ipv4.conf.default.secure_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.secure_redirects="$sysctl_net_ipv4_conf_default_secure_redirects_value"

#
# If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.secure_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.secure_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_secure_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_echo_ignore_broadcasts = 1
Rationale:
Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.
Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_echo_ignore_broadcasts
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.icmp_echo_ignore_broadcasts%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_icmp_echo_ignore_broadcasts.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

- name: Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts
    replace: '#net.ipv4.icmp_echo_ignore_broadcasts'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: XCCDF Value sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_echo_ignore_broadcasts is set
  sysctl:
    name: net.ipv4.icmp_echo_ignore_broadcasts
    value: '{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_echo_ignore_broadcasts.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.icmp_echo_ignore_broadcasts" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value='1'


#
# Set runtime for net.ipv4.icmp_echo_ignore_broadcasts
#
/sbin/sysctl -q -n -w net.ipv4.icmp_echo_ignore_broadcasts="$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"

#
# If net.ipv4.icmp_echo_ignore_broadcasts present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.icmp_echo_ignore_broadcasts = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_echo_ignore_broadcasts")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_echo_ignore_broadcasts\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_echo_ignore_broadcasts\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_ignore_bogus_error_responses = 1
Rationale:
Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, Req-1.4.3, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.icmp_ignore_bogus_error_responses%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_icmp_ignore_bogus_error_responses.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity

- name: Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses
    from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses
    replace: '#net.ipv4.icmp_ignore_bogus_error_responses'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_ignore_bogus_error_responses is set
  sysctl:
    name: net.ipv4.icmp_ignore_bogus_error_responses
    value: '{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.icmp_ignore_bogus_error_responses" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value='1'


#
# Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
#
/sbin/sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses="$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"

#
# If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.icmp_ignore_bogus_error_responses = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_ignore_bogus_error_responses")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_ignore_bogus_error_responses\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_ignore_bogus_error_responses\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces   [ref]

To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.tcp_syncookies = 1
Rationale:
A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001095, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.1, SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.tcp_syncookies%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_tcp_syncookies.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.tcp_syncookies.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies

- name: Comment out any occurrences of net.ipv4.tcp_syncookies from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.tcp_syncookies
    replace: '#net.ipv4.tcp_syncookies'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies
- name: XCCDF Value sysctl_net_ipv4_tcp_syncookies_value # promote to variable
  set_fact:
    sysctl_net_ipv4_tcp_syncookies_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.tcp_syncookies is set
  sysctl:
    name: net.ipv4.tcp_syncookies
    value: '{{ sysctl_net_ipv4_tcp_syncookies_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.tcp_syncookies from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.tcp_syncookies.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.tcp_syncookies" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_tcp_syncookies_value='1'


#
# Set runtime for net.ipv4.tcp_syncookies
#
/sbin/sysctl -q -n -w net.ipv4.tcp_syncookies="$sysctl_net_ipv4_tcp_syncookies_value"

#
# If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.tcp_syncookies = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.tcp_syncookies")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_tcp_syncookies_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.tcp_syncookies\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.tcp_syncookies\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Parameters for Hosts Only   Group contains 2 rules
[ref]   If the system is not going to be used as a router, then setting certain kernel parameters ensure that the host will not perform routing of network traffic.

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.send_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, 1.4.2, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.all.send_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_all_send_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.send_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.send_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.send_redirects
    replace: '#net.ipv4.conf.all.send_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

- name: Ensure sysctl net.ipv4.conf.all.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.all.send_redirects
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.all.send_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.send_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.send_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.conf.all.send_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.send_redirects="0"

#
# If net.ipv4.conf.all.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.send_redirects = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.send_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.send_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command:
$ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.send_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,net.ipv4.conf.default.send_redirects%3D0%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_net_ipv4_conf_default_send_redirects.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.send_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.send_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.send_redirects
    replace: '#net.ipv4.conf.default.send_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

- name: Ensure sysctl net.ipv4.conf.default.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.default.send_redirects
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of net.ipv4.conf.default.send_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.send_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.send_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.conf.default.send_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.send_redirects="0"

#
# If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.send_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.send_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   nftables   Group contains 1 rule
[ref]   If firewalld or iptables are being used in your environment, please follow the guidance in their respective section and pass-over the guidance in this section.

nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables. The biggest change with the successor nftables is its simplicity. With iptables, we have to configure every single rule and use the syntax which can be compared with normal commands. With nftables, the simpler syntax, much like BPF (Berkely Packet Filter) means shorter lines and less repetition. Support for nftables should also be compiled into the kernel, together with the related nftables modules.

It is available in Linux kernels >= 3.13. Please ensure that your kernel supports nftables before choosing this option.

Rule   Verify nftables Service is Disabled   [ref]

nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables. The nftables service can be disabled with the following command:
systemctl disable nftables
Rationale:
Running both firewalld and nftables may lead to conflict. nftables is actually one of the backends for firewalld management tools.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_nftables_disabled
Identifiers and References

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
      - name: nftables.service
        enabled: false
        mask: true
      - name: nftables.socket
        enabled: false
        mask: true


[customizations.services]
disabled = ["nftables"]

Complexity:low
Disruption:low
Strategy:enable
include disable_nftables

class disable_nftables {
  service {'nftables':
    enable => false,
    ensure => 'stopped',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Block Disable service nftables
  block:

  - name: Disable service nftables
    block:

    - name: Disable service nftables
      systemd:
        name: nftables.service
        enabled: 'no'
        state: stopped
        masked: 'yes'
    rescue:

    - name: Intentionally ignored previous 'Disable service nftables' failure, service
        was already disabled
      meta: noop
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

- name: Unit Socket Exists - nftables.socket
  command: systemctl list-unit-files nftables.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

- name: Disable socket nftables
  systemd:
    name: nftables.socket
    enabled: 'no'
    state: stopped
    masked: 'yes'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"nftables.socket" in socket_file_exists.stdout_lines[1]'
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_disabled

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" stop 'nftables.service'
"$SYSTEMCTL_EXEC" disable 'nftables.service'
"$SYSTEMCTL_EXEC" mask 'nftables.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files nftables.socket; then
    "$SYSTEMCTL_EXEC" stop 'nftables.socket'
    "$SYSTEMCTL_EXEC" mask 'nftables.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'nftables.service' || true

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Uncommon Network Protocols   Group contains 2 rules
[ref]   The system includes support for several network protocols which are not commonly used. Although security vulnerabilities in kernel networking code are not frequently discovered, the consequences can be dramatic. Ensuring uncommon network protocols are disabled reduces the system's risk to attacks targeted at its implementation of those protocols.
Warning:  Although these protocols are not commonly used, avoid disruption in your network environment by ensuring they are not needed prior to disabling them.

Rule   Disable DCCP Support   [ref]

The Datagram Congestion Control Protocol (DCCP) is a relatively new transport layer protocol, designed to support streaming media and telephony. To configure the system to prevent the dccp kernel module from being loaded, add the following line to the file /etc/modprobe.d/dccp.conf:
install dccp /bin/true
Rationale:
Disabling DCCP protects the system against exploitation of any flaws in its implementation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_dccp_disabled
Identifiers and References

References:  11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, CCI-001958, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4.2, 1.4.2, SRG-OS-000096-GPOS-00050, SRG-OS-000378-GPOS-00163


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,install%20dccp%20/bin/true%0Ablacklist%20dccp%0A
        mode: 0644
        path: /etc/modprobe.d/dccp.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'dccp' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/dccp.conf
    regexp: install\s+dccp
    line: install dccp /bin/true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1
  - NIST-800-171-3.4.6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - kernel_module_dccp_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install dccp" /etc/modprobe.d/dccp.conf ; then
	
	sed -i 's#^install dccp.*#install dccp /bin/true#g' /etc/modprobe.d/dccp.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/dccp.conf
	echo "install dccp /bin/true" >> /etc/modprobe.d/dccp.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable SCTP Support   [ref]

The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. To configure the system to prevent the sctp kernel module from being loaded, add the following line to the file /etc/modprobe.d/sctp.conf:
install sctp /bin/true
Rationale:
Disabling SCTP protects the system against exploitation of any flaws in its implementation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_sctp_disabled
Identifiers and References

References:  11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, CCI-000381, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4.2, 1.4.2, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,install%20sctp%20/bin/true%0Ablacklist%20sctp%0A
        mode: 0644
        path: /etc/modprobe.d/sctp.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'sctp' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/sctp.conf
    regexp: install\s+sctp
    line: install sctp /bin/true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1
  - NIST-800-171-3.4.6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - kernel_module_sctp_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install sctp" /etc/modprobe.d/sctp.conf ; then
	
	sed -i 's#^install sctp.*#install sctp /bin/true#g' /etc/modprobe.d/sctp.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/sctp.conf
	echo "install sctp /bin/true" >> /etc/modprobe.d/sctp.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   File Permissions and Masks   Group contains 6 groups and 38 rules
[ref]   Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access.

Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn.

The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Fedora installations:
$ mount -t xfs | awk '{print $3}'
For any systems that use a different local filesystem type, modify this command as appropriate.
Group   Verify Permissions on Important Files and Directories   Group contains 1 group and 30 rules
[ref]   Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.
Group   Verify Permissions on Files with Local Account Information and Credentials   Group contains 24 rules

Rule   Verify Group Who Owns Backup group File   [ref]

To properly set the group owner of /etc/group-, run the command:
$ sudo chgrp root /etc/group-
Rationale:
The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_group
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group-
  stat:
    path: /etc/group-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/group-
  file:
    path: /etc/group-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/group-

Rule   Verify Group Who Owns Backup gshadow File   [ref]

To properly set the group owner of /etc/gshadow-, run the command:
$ sudo chgrp root /etc/gshadow-
Rationale:
The /etc/gshadow- file is a backup of /etc/gshadow, and as such, it contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_gshadow
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow-
  stat:
    path: /etc/gshadow-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/gshadow-
  file:
    path: /etc/gshadow-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/gshadow-

Rule   Verify Group Who Owns Backup passwd File   [ref]

To properly set the group owner of /etc/passwd-, run the command:
$ sudo chgrp root /etc/passwd-
Rationale:
The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_passwd
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd-
  stat:
    path: /etc/passwd-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/passwd-
  file:
    path: /etc/passwd-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/passwd-

Rule   Verify User Who Owns Backup shadow File   [ref]

To properly set the group owner of /etc/shadow-, run the command:
$ sudo chgrp root /etc/shadow-
Rationale:
The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_shadow
Identifiers and References

References:  Req-8.7, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow-
  stat:
    path: /etc/shadow-
  register: file_exists
  tags:
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/shadow-
  file:
    path: /etc/shadow-
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/shadow-

Rule   Verify Group Who Owns group File   [ref]

To properly set the group owner of /etc/group, run the command:
$ sudo chgrp root /etc/group
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_group
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/group
  file:
    path: /etc/group
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/group

Rule   Verify Group Who Owns gshadow File   [ref]

To properly set the group owner of /etc/gshadow, run the command:
$ sudo chgrp root /etc/gshadow
Rationale:
The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_gshadow
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/gshadow
  file:
    path: /etc/gshadow
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/gshadow

Rule   Verify Group Who Owns passwd File   [ref]

To properly set the group owner of /etc/passwd, run the command:
$ sudo chgrp root /etc/passwd
Rationale:
The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/passwd

Rule   Verify Group Who Owns shadow File   [ref]

To properly set the group owner of /etc/shadow, run the command:
$ sudo chgrp root /etc/shadow
Rationale:
The /etc/shadow file stores password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/shadow
  file:
    path: /etc/shadow
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_groupowner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chgrp 0 /etc/shadow

Rule   Verify User Who Owns Backup group File   [ref]

To properly set the owner of /etc/group-, run the command:
$ sudo chown root /etc/group- 
Rationale:
The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_backup_etc_group
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group-
  stat:
    path: /etc/group-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/group-
  file:
    path: /etc/group-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/group-

Rule   Verify User Who Owns Backup gshadow File   [ref]

To properly set the owner of /etc/gshadow-, run the command:
$ sudo chown root /etc/gshadow- 
Rationale:
The /etc/gshadow- file is a backup of /etc/gshadow, and as such, it contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_backup_etc_gshadow
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow-
  stat:
    path: /etc/gshadow-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/gshadow-
  file:
    path: /etc/gshadow-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/gshadow-

Rule   Verify User Who Owns Backup passwd File   [ref]

To properly set the owner of /etc/passwd-, run the command:
$ sudo chown root /etc/passwd- 
Rationale:
The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_backup_etc_passwd
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd-
  stat:
    path: /etc/passwd-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/passwd-
  file:
    path: /etc/passwd-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/passwd-

Rule   Verify Group Who Owns Backup shadow File   [ref]

To properly set the owner of /etc/shadow-, run the command:
$ sudo chown root /etc/shadow- 
Rationale:
The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_backup_etc_shadow
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow-
  stat:
    path: /etc/shadow-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/shadow-
  file:
    path: /etc/shadow-
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/shadow-

Rule   Verify User Who Owns group File   [ref]

To properly set the owner of /etc/group, run the command:
$ sudo chown root /etc/group 
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_group
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/group
  file:
    path: /etc/group
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/group

Rule   Verify User Who Owns gshadow File   [ref]

To properly set the owner of /etc/gshadow, run the command:
$ sudo chown root /etc/gshadow 
Rationale:
The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_gshadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/gshadow
  file:
    path: /etc/gshadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/gshadow

Rule   Verify User Who Owns passwd File   [ref]

To properly set the owner of /etc/passwd, run the command:
$ sudo chown root /etc/passwd 
Rationale:
The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_passwd
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/passwd

Rule   Verify User Who Owns shadow File   [ref]

To properly set the owner of /etc/shadow, run the command:
$ sudo chown root /etc/shadow 
Rationale:
The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_shadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/shadow
  file:
    path: /etc/shadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/shadow

Rule   Verify Permissions on Backup group File   [ref]

To properly set the permissions of /etc/group-, run the command:
$ sudo chmod 0644 /etc/group-
Rationale:
The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_group
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group-
  stat:
    path: /etc/group-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group-
  file:
    path: /etc/group-
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xs,g-xws,o-xwt /etc/group-

Rule   Verify Permissions on Backup gshadow File   [ref]

To properly set the permissions of /etc/gshadow-, run the command:
$ sudo chmod 0000 /etc/gshadow-
Rationale:
The /etc/gshadow- file is a backup of /etc/gshadow, and as such, it contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_gshadow
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow-
  stat:
    path: /etc/gshadow-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - configure_strategy
  - file_permissions_backup_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow-
  file:
    path: /etc/gshadow-
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - configure_strategy
  - file_permissions_backup_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow-

Rule   Verify Permissions on Backup passwd File   [ref]

To properly set the permissions of /etc/passwd-, run the command:
$ sudo chmod 0644 /etc/passwd-
Rationale:
The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_passwd
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd-
  stat:
    path: /etc/passwd-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd-
  file:
    path: /etc/passwd-
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_backup_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xs,g-xws,o-xwt /etc/passwd-

Rule   Verify Permissions on Backup shadow File   [ref]

To properly set the permissions of /etc/shadow-, run the command:
$ sudo chmod 0000 /etc/shadow-
Rationale:
The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_shadow
Identifiers and References

References:  CCI-002223, AC-6 (1), Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow-
  stat:
    path: /etc/shadow-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/shadow-
  file:
    path: /etc/shadow-
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_backup_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow-

Rule   Verify Permissions on group File   [ref]

To properly set the permissions of /etc/passwd, run the command:
$ sudo chmod 0644 /etc/passwd
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_group
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
  file:
    path: /etc/group
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xs,g-xws,o-xwt /etc/group

Rule   Verify Permissions on gshadow File   [ref]

To properly set the permissions of /etc/gshadow, run the command:
$ sudo chmod 0000 /etc/gshadow
Rationale:
The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow
  file:
    path: /etc/gshadow
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow

Rule   Verify Permissions on passwd File   [ref]

To properly set the permissions of /etc/passwd, run the command:
$ sudo chmod 0644 /etc/passwd
Rationale:
If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_passwd
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
  file:
    path: /etc/passwd
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xs,g-xws,o-xwt /etc/passwd

Rule   Verify Permissions on shadow File   [ref]

To properly set the permissions of /etc/shadow, run the command:
$ sudo chmod 0000 /etc/shadow
Rationale:
The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_shadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/shadow
  file:
    path: /etc/shadow
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow

Rule   Verify that All World-Writable Directories Have Sticky Bits Set   [ref]

When the so-called 'sticky bit' is set on a directory, only the owner of a given file may remove that file from the directory. Without the sticky bit, any user with write access to a directory may remove any file in the directory. Setting the sticky bit prevents users from removing each other's files. In cases where there is no reason for a directory to be world-writable, a better solution is to remove that permission rather than to set the sticky bit. However, if a directory is used by a particular application, consult that application's documentation instead of blindly changing modes.
To set the sticky bit on a world-writable directory DIR, run the following command:
$ sudo chmod +t DIR
Rationale:
Failing to set the sticky bit on public directories allows unauthorized users to delete files in the directory structure.

The only authorized public directories are those temporary directories supplied with the system, or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system, by users for temporary file storage (such as /tmp), and for directories requiring global read/write access.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_dir_perms_world_writable_sticky_bits
Identifiers and References

References:  BP28(R40), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-001090, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000138-GPOS-00069

Rule   Ensure No World-Writable Files Exist   [ref]

It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account. Finally, this applies to real files and not virtual files that are a part of pseudo file systems such as sysfs or procfs.
Rationale:
Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_unauthorized_world_writable
Identifiers and References

References:  BP28(R40), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6



find / -xdev -type f -perm -002 -exec chmod o-w {} \;

Rule   Ensure All Files Are Owned by a Group   [ref]

If any files are not owned by a group, then the cause of their lack of group-ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate group. The following command will discover and print any files on local partitions which do not belong to a valid group:
$ df --local -P | awk '{if (NR!=1) print $6}' | sudo xargs -I '{}' find '{}' -xdev -nogroup
To search all filesystems on a system including network mounted filesystems the following command can be run manually for each partition:
$ sudo find PARTITION -xdev -nogroup
Warning:  This rule only considers local groups. If you have your groups defined outside /etc/group, the rule won't consider those.
Rationale:
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_ungroupowned
Identifiers and References

References:  BP28(R55), 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10, CCI-000366, CCI-002165, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3, 2.2.6, SRG-OS-000480-GPOS-00227

Rule   Ensure All Files Are Owned by a User   [ref]

If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user. The following command will discover and print any files on local partitions which do not belong to a valid user:
$ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nouser
To search all filesystems on a system including network mounted filesystems the following command can be run manually for each partition:
$ sudo find PARTITION -xdev -nouser
Warning:  For this rule to evaluate centralized user accounts, getent must be working properly so that running the command
getent passwd
returns a list of all users in your organization. If using the System Security Services Daemon (SSSD),
enumerate = true
must be configured in your organization's domain to return a complete list of users
Warning:  Enabling this rule will result in slower scan times depending on the size of your organization and number of centralized users.
Rationale:
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_files_unowned_by_user
Identifiers and References

References:  BP28(R55), 11, 12, 13, 14, 15, 16, 18, 3, 5, 9, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, CCI-000366, CCI-002165, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, 2.2.6, SRG-OS-000480-GPOS-00227

Group   Restrict Dynamic Mounting and Unmounting of Filesystems   Group contains 3 rules
[ref]   Linux includes a number of facilities for the automated addition and removal of filesystems on a running system. These facilities may be necessary in many environments, but this capability also carries some risk -- whether direct risk from allowing users to introduce arbitrary filesystems, or risk that software flaws in the automated mount facility itself could allow an attacker to compromise the system.

This command can be used to list the types of filesystems that are available to the currently executing kernel:
$ find /lib/modules/`uname -r`/kernel/fs -type f -name '*.ko'
If these filesystems are not required then they can be explicitly disabled in a configuratio file in /etc/modprobe.d.

Rule   Disable Mounting of cramfs   [ref]

To configure the system to prevent the cramfs kernel module from being loaded, add the following line to the file /etc/modprobe.d/cramfs.conf:
install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem. The cramfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems. A cramfs image can be used without having to first decompress the image.
Rationale:
Removing support for unneeded filesystem types reduces the local attack surface of the server.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_cramfs_disabled
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, CCI-000381, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,install%20cramfs%20/bin/true%0Ablacklist%20cramfs%0A
        mode: 0644
        path: /etc/modprobe.d/cramfs.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'cramfs' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/cramfs.conf
    regexp: install\s+cramfs
    line: install cramfs /bin/true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - kernel_module_cramfs_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install cramfs" /etc/modprobe.d/cramfs.conf ; then
	
	sed -i 's#^install cramfs.*#install cramfs /bin/true#g' /etc/modprobe.d/cramfs.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/cramfs.conf
	echo "install cramfs /bin/true" >> /etc/modprobe.d/cramfs.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Mounting of squashfs   [ref]

To configure the system to prevent the squashfs kernel module from being loaded, add the following line to the file /etc/modprobe.d/squashfs.conf:
install squashfs /bin/true
This effectively prevents usage of this uncommon filesystem. The squashfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems (similar to cramfs). A squashfs image can be used without having to first decompress the image.
Rationale:
Removing support for unneeded filesystem types reduces the local attack surface of the system.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_squashfs_disabled
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,install%20squashfs%20/bin/true%0Ablacklist%20squashfs%0A
        mode: 0644
        path: /etc/modprobe.d/squashfs.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'squashfs' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/squashfs.conf
    regexp: install\s+squashfs
    line: install squashfs /bin/true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - kernel_module_squashfs_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install squashfs" /etc/modprobe.d/squashfs.conf ; then
	
	sed -i 's#^install squashfs.*#install squashfs /bin/true#g' /etc/modprobe.d/squashfs.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/squashfs.conf
	echo "install squashfs /bin/true" >> /etc/modprobe.d/squashfs.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Mounting of udf   [ref]

To configure the system to prevent the udf kernel module from being loaded, add the following line to the file /etc/modprobe.d/udf.conf:
install udf /bin/true
This effectively prevents usage of this uncommon filesystem. The udf filesystem type is the universal disk format used to implement the ISO/IEC 13346 and ECMA-167 specifications. This is an open vendor filesystem type for data storage on a broad range of media. This filesystem type is neccessary to support writing DVDs and newer optical disc formats.
Rationale:
Removing support for unneeded filesystem types reduces the local attack surface of the system.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_kernel_module_udf_disabled
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,install%20udf%20/bin/true%0Ablacklist%20udf%0A
        mode: 0644
        path: /etc/modprobe.d/udf.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: Ensure kernel module 'udf' is disabled
  lineinfile:
    create: true
    dest: /etc/modprobe.d/udf.conf
    regexp: install\s+udf
    line: install udf /bin/true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.4.6
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - kernel_module_udf_disabled
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if LC_ALL=C grep -q -m 1 "^install udf" /etc/modprobe.d/udf.conf ; then
	
	sed -i 's#^install udf.*#install udf /bin/true#g' /etc/modprobe.d/udf.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/udf.conf
	echo "install udf /bin/true" >> /etc/modprobe.d/udf.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Restrict Partition Mount Options   Group contains 2 rules
[ref]   System partitions can be mounted with certain options that limit what files on those partitions can do. These options are set in the /etc/fstab configuration file, and can be used to make certain types of malicious behavior more difficult.

Rule   Add nodev Option to /home   [ref]

The nodev mount option can be used to prevent device files from being created in /home. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /home.
Rationale:
The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_home_nodev
Identifiers and References

References:  BP28(R12), SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /home --mountoptions="nodev"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nodev Option to /home: Check information associated to mountpoint'
  command: findmnt --fstab '/home'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_home_nodev
  - no_reboot_needed
  - unknown_severity

- name: 'Add nodev Option to /home: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_home_nodev
  - no_reboot_needed
  - unknown_severity

- name: 'Add nodev Option to /home: If /home not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /home
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_home_nodev
  - no_reboot_needed
  - unknown_severity

- name: 'Add nodev Option to /home: Make sure nodev option is part of the to /home
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nodev" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_home_nodev
  - no_reboot_needed
  - unknown_severity

- name: 'Add nodev Option to /home: Ensure /home is mounted with nodev option'
  mount:
    path: /home
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_home_nodev
  - no_reboot_needed
  - unknown_severity

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/home")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/home' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /home)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /home  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nodev"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
    fi


    if mkdir -p "/home"; then
        if mountpoint -q "/home"; then
            mount -o remount --target "/home"
        fi
    fi
}

perform_remediation

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Add nosuid Option to /home   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /home. The SUID and SGID permissions should not be required in these user data directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /home.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from user home directory partitions.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_home_nosuid
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:high
Strategy:enable

part /home --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /home: Check information associated to mountpoint'
  command: findmnt --fstab '/home'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_home_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /home: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_home_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /home: If /home not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /home
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_home_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /home: Make sure nosuid option is part of the to /home
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_home_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /home: Ensure /home is mounted with nosuid option'
  mount:
    path: /home
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_home_nosuid
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/home")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/home' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /home)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /home  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/home"; then
        if mountpoint -q "/home"; then
            mount -o remount --target "/home"
        fi
    fi
}

perform_remediation

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Restrict Programs from Dangerous Execution Patterns   Group contains 1 group and 3 rules
[ref]   The recommendations in this section are designed to ensure that the system's features to protect against potentially dangerous program execution are activated. These protections are applied at the system initialization or kernel level, and defend against certain types of badly-configured or compromised programs.
Group   Enable ExecShield   Group contains 3 rules
[ref]   ExecShield describes kernel features that provide protection against exploitation of memory corruption errors such as buffer overflows. These features include random placement of the stack and other memory regions, prevention of execution in memory that should only hold data, and special handling of text buffers. These protections are enabled by default on 32-bit systems and controlled through sysctl variables kernel.exec-shield and kernel.randomize_va_space. On the latest 64-bit systems, kernel.exec-shield cannot be enabled or disabled with sysctl.

Rule   Enable ExecShield via sysctl   [ref]

By default on Fedora 64-bit systems, ExecShield is enabled and can only be disabled if the hardware does not support ExecShield or is disabled in /etc/default/grub.
Rationale:
ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places a process's memory regions such as the stack and heap higher than this address, the hardware prevents execution in that address range. This is enabled by default on the latest Red Hat and Fedora systems if supported by the hardware.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_exec_shield
Identifiers and References

References:  12, 15, 8, APO13.01, DSS05.02, 3.1.7, CCI-002530, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, SC-39, CM-6(a), PR.PT-4, SRG-OS-000433-GPOS-00192


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --remove-args="noexec"
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-39
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy
  - sysctl_kernel_exec_shield

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

grubby --update-kernel=ALL --remove-args=noexec

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Restrict Exposed Kernel Pointer Addresses Access   [ref]

To set the runtime status of the kernel.kptr_restrict kernel parameter, run the following command:
$ sudo sysctl -w kernel.kptr_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.kptr_restrict = 1
Rationale:
Exposing kernel pointers (through procfs or seq_printf()) exposes kernel writeable structures which may contain functions pointers. If a write vulnerability occurs in the kernel, allowing write access to any of this structure, the kernel can be compromised. This option disallow any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with 0.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_kptr_restrict
Identifiers and References

References:  BP28(R23), CCI-002824, CCI-000366, CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4, SC-30, SC-30(2), SC-30(5), CM-6(a), SRG-OS-000132-GPOS-00067, SRG-OS-000433-GPOS-00192, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,kernel.kptr_restrict%3D1%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_kptr_restrict.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*kernel.kptr_restrict.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - NIST-800-53-SC-30(5)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_kptr_restrict

- name: Comment out any occurrences of kernel.kptr_restrict from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.kptr_restrict
    replace: '#kernel.kptr_restrict'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - NIST-800-53-SC-30(5)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_kptr_restrict
- name: XCCDF Value sysctl_kernel_kptr_restrict_value # promote to variable
  set_fact:
    sysctl_kernel_kptr_restrict_value: !!str 1
  tags:
    - always

- name: Ensure sysctl kernel.kptr_restrict is set
  sysctl:
    name: kernel.kptr_restrict
    value: '{{ sysctl_kernel_kptr_restrict_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - NIST-800-53-SC-30(5)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_kptr_restrict

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of kernel.kptr_restrict from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*kernel.kptr_restrict.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "kernel.kptr_restrict" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_kernel_kptr_restrict_value='1'


#
# Set runtime for kernel.kptr_restrict
#
/sbin/sysctl -q -n -w kernel.kptr_restrict="$sysctl_kernel_kptr_restrict_value"

#
# If kernel.kptr_restrict present in /etc/sysctl.conf, change value to appropriate value
#	else, add "kernel.kptr_restrict = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^kernel.kptr_restrict")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_kernel_kptr_restrict_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^kernel.kptr_restrict\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^kernel.kptr_restrict\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Randomized Layout of Virtual Address Space   [ref]

To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command:
$ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.randomize_va_space = 2
Rationale:
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space
Identifiers and References

References:  BP28(R23), 3.1.7, CCI-000366, CCI-002824, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4, SC-30, SC-30(2), CM-6(a), Req-2.2.1, 2.2.3, SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,kernel.randomize_va_space%3D2%0A
        mode: 0644
        path: /etc/sysctl.d/75-sysctl_kernel_randomize_va_space.conf
        overwrite: true

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*kernel.randomize_va_space.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-2.2.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Comment out any occurrences of kernel.randomize_va_space from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.randomize_va_space
    replace: '#kernel.randomize_va_space'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-2.2.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Ensure sysctl kernel.randomize_va_space is set to 2
  sysctl:
    name: kernel.randomize_va_space
    value: '2'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-2.2.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Comment out any occurrences of kernel.randomize_va_space from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*kernel.randomize_va_space.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "kernel.randomize_va_space" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.randomize_va_space
#
/sbin/sysctl -q -n -w kernel.randomize_va_space="2"

#
# If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
#	else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^kernel.randomize_va_space")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "2"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^kernel.randomize_va_space\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^kernel.randomize_va_space\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   SELinux   Group contains 5 rules
[ref]   SELinux is a feature of the Linux kernel which can be used to guard against misconfigured or compromised programs. SELinux enforces the idea that programs should be limited in what files they can access and what actions they can take.

The default SELinux policy, as configured on Fedora, has been sufficiently developed and debugged that it should be usable on almost any system with minimal configuration and a small amount of system administrator training. This policy prevents system services - including most of the common network-visible services such as mail servers, FTP servers, and DNS servers - from accessing files which those services have no valid reason to access. This action alone prevents a huge amount of possible damage from network attacks against services, from trojaned software, and so forth.

This guide recommends that SELinux be enabled using the default (targeted) policy on every Fedora system, unless that system has unusual requirements which make a stronger policy appropriate.

Rule   Install libselinux Package   [ref]

The libselinux package can be installed with the following command:
$ sudo dnf install libselinux
Rationale:
Security-enhanced Linux is a feature of the Linux kernel and a number of utilities with enhanced security functionality designed to add mandatory access controls to Linux. The libselinux package contains the core library of the Security-enhanced Linux system.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_libselinux_installed
Identifiers and References

Complexity:low
Disruption:low
Strategy:enable

package --add=libselinux


[[packages]]
name = "libselinux"
version = "*"

Complexity:low
Disruption:low
Strategy:enable
include install_libselinux

class install_libselinux {
  package { 'libselinux':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure libselinux is installed
  package:
    name: libselinux
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - enable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_libselinux_installed

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if ! rpm -q --quiet "libselinux" ; then
    dnf install -y "libselinux"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Uninstall mcstrans Package   [ref]

The mcstransd daemon provides category label information to client processes requesting information. The label translations are defined in /etc/selinux/targeted/setrans.conf. The mcstrans package can be removed with the following command:
$ sudo dnf erase mcstrans
Rationale:
Since this service is not used very often, disable it to reduce the amount of potentially vulnerable code running on the system.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_mcstrans_removed
Identifiers and References

Complexity:low
Disruption:low
Strategy:disable

package --remove=mcstrans

Complexity:low
Disruption:low
Strategy:disable
include remove_mcstrans

class remove_mcstrans {
  package { 'mcstrans':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure mcstrans is removed
  package:
    name: mcstrans
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_mcstrans_removed

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# CAUTION: This remediation script will remove mcstrans
#	   from the system, and may remove any packages
#	   that depend on mcstrans. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "mcstrans" ; then

    dnf remove -y "mcstrans"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure SELinux Not Disabled in /etc/default/grub   [ref]

SELinux can be disabled at boot time by an argument in /etc/default/grub. Remove any instances of selinux=0 from the kernel arguments in that file to prevent SELinux from being disabled at boot.
Rationale:
Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_enable_selinux
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-000022, CCI-000032, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-3, AC-3(3)(a), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure SELinux Not Disabled in /etc/default/grub - Find /etc/grub.d/ files
  ansible.builtin.find:
    paths:
    - /etc/grub.d/
    follow: true
  register: result_grub_d
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure SELinux Not Disabled in /etc/default/grub - Ensure SELinux Not Disabled
    in /etc/grub.d/ files
  ansible.builtin.replace:
    dest: '{{ item.path }}'
    regexp: (selinux|enforcing)=0
  with_items:
  - '{{ result_grub_d.files }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure SELinux Not Disabled in /etc/default/grub - Check if /etc/grub2.cfg
    exists
  ansible.builtin.stat:
    path: /etc/grub2.cfg
  register: result_grub2_cfg_present
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure SELinux Not Disabled in /etc/default/grub - Check if /etc/default/grub
    exists
  ansible.builtin.stat:
    path: /etc/default/grub
  register: result_default_grub_present
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure SELinux Not Disabled in /etc/default/grub - Ensure SELinux Not Disabled
    in /etc/grub2.cfg
  ansible.builtin.replace:
    dest: /etc/grub2.cfg
    regexp: (selinux|enforcing)=0
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  - result_grub2_cfg_present.stat.exists
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure SELinux Not Disabled in /etc/default/grub - Ensure SELinux Not Disabled
    in /etc/default/grub
  ansible.builtin.replace:
    dest: /etc/default/grub
    regexp: (selinux|enforcing)=0
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  - result_default_grub_present.stat.exists
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - grub2_enable_selinux
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q grub2-common; }; then

sed -i --follow-symlinks "s/selinux=0//gI" /etc/default/grub /etc/grub2.cfg /etc/grub.d/*
sed -i --follow-symlinks "s/enforcing=0//gI" /etc/default/grub /etc/grub2.cfg /etc/grub.d/*

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure SELinux Policy   [ref]

The SELinux targeted policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in /etc/selinux/config:
SELINUXTYPE=targeted
Other policies, such as mls, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.
Rationale:
Setting the SELinux policy to targeted or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services.

Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in permissive mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to targeted.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_selinux_policytype
Identifiers and References

References:  BP28(R66), 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-002165, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000445-GPOS-00199


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: XCCDF Value var_selinux_policy_name # promote to variable
  set_fact:
    var_selinux_policy_name: !!str targeted
  tags:
    - always

- name: Configure SELinux Policy
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/selinux/config
      create: false
      regexp: ^SELINUXTYPE=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: false
      regexp: ^SELINUXTYPE=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: true
      regexp: ^SELINUXTYPE=
      line: SELINUXTYPE={{ var_selinux_policy_name }}
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - NIST-800-53-AU-9
  - NIST-800-53-SC-7(21)
  - low_complexity
  - low_disruption
  - medium_severity
  - reboot_required
  - restrict_strategy
  - selinux_policytype

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_selinux_policy_name='targeted'


if [ -e "/etc/selinux/config" ] ; then
    
    LC_ALL=C sed -i "/^SELINUXTYPE=/Id" "/etc/selinux/config"
else
    touch "/etc/selinux/config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/selinux/config"

cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUXTYPE=$var_selinux_policy_name" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure SELinux State is Enforcing   [ref]

The SELinux state should be set to enforcing at system boot time. In the file /etc/selinux/config, add or correct the following line to configure the system to boot into enforcing mode:
SELINUX=enforcing
Rationale:
Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_selinux_state
Identifiers and References

References:  BP28(R4), BP28(R66), 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-001084, CCI-002165, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000445-GPOS-00199, SRG-OS-000134-GPOS-00068


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_selinux_state # promote to variable
  set_fact:
    var_selinux_state: !!str enforcing
  tags:
    - always

- name: Ensure SELinux State is Enforcing
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/selinux/config
      create: false
      regexp: ^SELINUX=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: false
      regexp: ^SELINUX=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: true
      regexp: ^SELINUX=
      line: SELINUX={{ var_selinux_state }}
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - NIST-800-53-AU-9
  - NIST-800-53-SC-7(21)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - selinux_state

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_selinux_state='enforcing'


if [ -e "/etc/selinux/config" ] ; then
    
    LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
else
    touch "/etc/selinux/config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/selinux/config"

cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUX=$var_selinux_state" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"

fixfiles onboot
fixfiles -f relabel

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Services   Group contains 36 groups and 81 rules
[ref]   The best protection against vulnerable software is running less software. This section describes how to review the software which Fedora installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Fedora system and provides guidance about which ones can be safely disabled.

Fedora provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Fedora systems, it is highly recommended to select the minimal packages and then build up the system from there.
Group   Cron and At Daemons   Group contains 1 group and 24 rules
[ref]   The cron and at services are used to allow commands to be executed at a later time. The cron service is required by almost all systems to perform necessary maintenance tasks, while at may or may not be required on a given system. Both daemons should be configured defensively.
Group   Restrict at and cron to Authorized Users if Necessary   Group contains 6 rules
[ref]   The /etc/cron.allow and /etc/at.allow files contain lists of users who are allowed to use cron and at to delay execution of processes. If these files exist and if the corresponding files /etc/cron.deny and /etc/at.deny do not exist, then only users listed in the relevant allow files can run the crontab and at commands to submit jobs to be run at scheduled intervals. On many systems, only the system administrator needs the ability to schedule jobs. Note that even if a given user is not listed in cron.allow, cron jobs can still be run as that user. The cron.allow file controls only administrative access to the crontab command for scheduling and modifying cron jobs.

To restrict at and cron to only authorized users:
  • Remove the cron.deny file:
    $ sudo rm /etc/cron.deny
  • Edit /etc/cron.allow, adding one line for each user allowed to use the crontab command to create cron jobs.
  • Remove the at.deny file:
    $ sudo rm /etc/at.deny
  • Edit /etc/at.allow, adding one line for each user allowed to use the at command to create at jobs.

Rule   Verify Group Who Owns /etc/at.allow file   [ref]

If /etc/at.allow exists, it must be group-owned by root. To properly set the group owner of /etc/at.allow, run the command:
$ sudo chgrp root /etc/at.allow
Rationale:
If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_at_allow
Identifiers and References

References:  2.2.6


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/at.allow
  file:
    path: /etc/at.allow
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chgrp 0 /etc/at.allow

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns /etc/cron.allow file   [ref]

If /etc/cron.allow exists, it must be group-owned by root. To properly set the group owner of /etc/cron.allow, run the command:
$ sudo chgrp root /etc/cron.allow
Rationale:
If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_allow
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/cron.allow
  stat:
    path: /etc/cron.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/cron.allow
  file:
    path: /etc/cron.allow
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chgrp 0 /etc/cron.allow

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify User Who Owns /etc/at.allow file   [ref]

If /etc/at.allow exists, it must be owned by root. To properly set the owner of /etc/at.allow, run the command:
$ sudo chown root /etc/at.allow 
Rationale:
If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_at_allow
Identifiers and References

References:  2.2.6


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/at.allow
  file:
    path: /etc/at.allow
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chown 0 /etc/at.allow

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify User Who Owns /etc/cron.allow file   [ref]

If /etc/cron.allow exists, it must be owned by root. To properly set the owner of /etc/cron.allow, run the command:
$ sudo chown root /etc/cron.allow 
Rationale:
If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_allow
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/cron.allow
  stat:
    path: /etc/cron.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/cron.allow
  file:
    path: /etc/cron.allow
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chown 0 /etc/cron.allow

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on /etc/at.allow file   [ref]

If /etc/at.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/at.allow, run the command:
$ sudo chmod 0640 /etc/at.allow
Rationale:
If the permissions of the at.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_at_allow
Identifiers and References

References:  2.2.6


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/at.allow
  file:
    path: /etc/at.allow
    mode: u-xs,g-xws,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chmod u-xs,g-xws,o-xwrt /etc/at.allow

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on /etc/cron.allow file   [ref]

If /etc/cron.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/cron.allow, run the command:
$ sudo chmod 0640 /etc/cron.allow
Rationale:
If the permissions of the cron.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_allow
Identifiers and References

References:  2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/cron.allow
  stat:
    path: /etc/cron.allow
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/cron.allow
  file:
    path: /etc/cron.allow
    mode: u-xs,g-xws,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chmod u-xs,g-xws,o-xwrt /etc/cron.allow

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns cron.d   [ref]

To properly set the group owner of /etc/cron.d, run the command:
$ sudo chgrp root /etc/cron.d
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_d
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure group owner on /etc/cron.d/
  file:
    path: /etc/cron.d/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_cron_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.d/ -maxdepth 1 -type d -exec chgrp 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns cron.daily   [ref]

To properly set the group owner of /etc/cron.daily, run the command:
$ sudo chgrp root /etc/cron.daily
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_daily
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure group owner on /etc/cron.daily/
  file:
    path: /etc/cron.daily/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_cron_daily
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.daily/ -maxdepth 1 -type d -exec chgrp 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns cron.hourly   [ref]

To properly set the group owner of /etc/cron.hourly, run the command:
$ sudo chgrp root /etc/cron.hourly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_hourly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure group owner on /etc/cron.hourly/
  file:
    path: /etc/cron.hourly/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_cron_hourly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.hourly/ -maxdepth 1 -type d -exec chgrp 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns cron.monthly   [ref]

To properly set the group owner of /etc/cron.monthly, run the command:
$ sudo chgrp root /etc/cron.monthly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_monthly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure group owner on /etc/cron.monthly/
  file:
    path: /etc/cron.monthly/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_cron_monthly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.monthly/ -maxdepth 1 -type d -exec chgrp 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns cron.weekly   [ref]

To properly set the group owner of /etc/cron.weekly, run the command:
$ sudo chgrp root /etc/cron.weekly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_cron_weekly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure group owner on /etc/cron.weekly/
  file:
    path: /etc/cron.weekly/
    state: directory
    group: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_cron_weekly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.weekly/ -maxdepth 1 -type d -exec chgrp 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns Crontab   [ref]

To properly set the group owner of /etc/crontab, run the command:
$ sudo chgrp root /etc/crontab
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_crontab
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/crontab
  stat:
    path: /etc/crontab
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_crontab
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/crontab
  file:
    path: /etc/crontab
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_crontab
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chgrp 0 /etc/crontab

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on cron.d   [ref]

To properly set the owner of /etc/cron.d, run the command:
$ sudo chown root /etc/cron.d 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_d
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure owner on directory /etc/cron.d/
  file:
    path: /etc/cron.d/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_cron_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.d/ -maxdepth 1 -type d -exec chown 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on cron.daily   [ref]

To properly set the owner of /etc/cron.daily, run the command:
$ sudo chown root /etc/cron.daily 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_daily
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure owner on directory /etc/cron.daily/
  file:
    path: /etc/cron.daily/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_cron_daily
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.daily/ -maxdepth 1 -type d -exec chown 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on cron.hourly   [ref]

To properly set the owner of /etc/cron.hourly, run the command:
$ sudo chown root /etc/cron.hourly 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_hourly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure owner on directory /etc/cron.hourly/
  file:
    path: /etc/cron.hourly/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_cron_hourly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.hourly/ -maxdepth 1 -type d -exec chown 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on cron.monthly   [ref]

To properly set the owner of /etc/cron.monthly, run the command:
$ sudo chown root /etc/cron.monthly 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_monthly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure owner on directory /etc/cron.monthly/
  file:
    path: /etc/cron.monthly/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_cron_monthly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.monthly/ -maxdepth 1 -type d -exec chown 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on cron.weekly   [ref]

To properly set the owner of /etc/cron.weekly, run the command:
$ sudo chown root /etc/cron.weekly 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_cron_weekly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Ensure owner on directory /etc/cron.weekly/
  file:
    path: /etc/cron.weekly/
    state: directory
    owner: '0'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_cron_weekly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.weekly/ -maxdepth 1 -type d -exec chown 0 {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on crontab   [ref]

To properly set the owner of /etc/crontab, run the command:
$ sudo chown root /etc/crontab 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_crontab
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/crontab
  stat:
    path: /etc/crontab
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_crontab
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/crontab
  file:
    path: /etc/crontab
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_crontab
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chown 0 /etc/crontab

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.d   [ref]

To properly set the permissions of /etc/cron.d, run the command:
$ sudo chmod 0700 /etc/cron.d
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_d
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Set permissions for /etc/cron.d/
  file:
    path: /etc/cron.d/
    state: directory
    mode: u-s,g-xwrs,o-xwrt
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.d/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.daily   [ref]

To properly set the permissions of /etc/cron.daily, run the command:
$ sudo chmod 0700 /etc/cron.daily
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_daily
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Set permissions for /etc/cron.daily/
  file:
    path: /etc/cron.daily/
    state: directory
    mode: u-s,g-xwrs,o-xwrt
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_daily
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.daily/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.hourly   [ref]

To properly set the permissions of /etc/cron.hourly, run the command:
$ sudo chmod 0700 /etc/cron.hourly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_hourly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Set permissions for /etc/cron.hourly/
  file:
    path: /etc/cron.hourly/
    state: directory
    mode: u-s,g-xwrs,o-xwrt
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_hourly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.hourly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.monthly   [ref]

To properly set the permissions of /etc/cron.monthly, run the command:
$ sudo chmod 0700 /etc/cron.monthly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_monthly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Set permissions for /etc/cron.monthly/
  file:
    path: /etc/cron.monthly/
    state: directory
    mode: u-s,g-xwrs,o-xwrt
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_monthly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.monthly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on cron.weekly   [ref]

To properly set the permissions of /etc/cron.weekly, run the command:
$ sudo chmod 0700 /etc/cron.weekly
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_cron_weekly
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Set permissions for /etc/cron.weekly/
  file:
    path: /etc/cron.weekly/
    state: directory
    mode: u-s,g-xwrs,o-xwrt
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_cron_weekly
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/cron.weekly/ -maxdepth 1 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on crontab   [ref]

To properly set the permissions of /etc/crontab, run the command:
$ sudo chmod 0600 /etc/crontab
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_crontab
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/crontab
  stat:
    path: /etc/crontab
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_crontab
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/crontab
  file:
    path: /etc/crontab
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_crontab
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chmod u-xs,g-xwrs,o-xwrt /etc/crontab

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   DHCP   Group contains 1 group and 1 rule
[ref]   The Dynamic Host Configuration Protocol (DHCP) allows systems to request and obtain an IP address and other configuration parameters from a server.

This guide recommends configuring networking on clients by manually editing the appropriate files under /etc/sysconfig. Use of DHCP can make client systems vulnerable to compromise by rogue DHCP servers, and should be avoided unless necessary. If using DHCP is necessary, however, there are best practices that should be followed to minimize security risk.
Group   Disable DHCP Server   Group contains 1 rule
[ref]   The DHCP server dhcpd is not installed or activated by default. If the software was installed and activated, but the system does not need to act as a DHCP server, it should be disabled and removed.

Rule   Uninstall DHCP Server Package   [ref]

If the system does not need to act as a DHCP server, the dhcp package can be uninstalled. The dhcp package can be removed with the following command:
$ sudo dnf erase dhcp
Rationale:
Removing the DHCP server ensures that it cannot be easily or accidentally reactivated and disrupt network operation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_dhcp_removed
Identifiers and References

References:  BP28(R1), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=dhcp

Complexity:low
Disruption:low
Strategy:disable
include remove_dhcp

class remove_dhcp {
  package { 'dhcp':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure dhcp is removed
  package:
    name: dhcp
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_dhcp_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove dhcp
#	   from the system, and may remove any packages
#	   that depend on dhcp. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "dhcp" ; then

    dnf remove -y "dhcp"

fi
Group   DNS Server   Group contains 1 group and 1 rule
[ref]   Most organizations have an operational need to run at least one nameserver. However, there are many common attacks involving DNS server software, and this server software should be disabled on any system on which it is not needed.
Group   Disable DNS Server   Group contains 1 rule
[ref]   DNS software should be disabled on any systems which does not need to be a nameserver. Note that the BIND DNS server software is not installed on Fedora by default. The remainder of this section discusses secure configuration of systems which must be nameservers.

Rule   Uninstall bind Package   [ref]

The named service is provided by the bind package. The bind package can be removed with the following command:
$ sudo dnf erase bind
Rationale:
If there is no need to make DNS server software available, removing it provides a safeguard against its activation.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_bind_removed
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=bind

Complexity:low
Disruption:low
Strategy:disable
include remove_bind

class remove_bind {
  package { 'bind':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure bind is removed
  package:
    name: bind
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_bind_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove bind
#	   from the system, and may remove any packages
#	   that depend on bind. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "bind" ; then

    dnf remove -y "bind"

fi
Group   FTP Server   Group contains 1 group and 1 rule
[ref]   FTP is a common method for allowing remote access to files. Like telnet, the FTP protocol is unencrypted, which means that passwords and other data transmitted during the session can be captured and that the session is vulnerable to hijacking. Therefore, running the FTP server software is not recommended.

However, there are some FTP server configurations which may be appropriate for some environments, particularly those which allow only read-only anonymous access as a means of downloading data available to the public.
Group   Disable vsftpd if Possible   Group contains 1 rule
[ref]   To minimize attack surface, disable vsftpd if at all possible.

Rule   Uninstall vsftpd Package   [ref]

The vsftpd package can be removed with the following command:
 $ sudo dnf erase vsftpd
Rationale:
Removing the vsftpd package decreases the risk of its accidental activation.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_vsftpd_removed
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000197, CCI-000366, CCI-000381, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), IA-5(1).1(v), CM-7, CM-7.1(ii), PR.IP-1, PR.PT-3, 2.2.4, SRG-OS-000074-GPOS-00042, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:disable

package --remove=vsftpd

Complexity:low
Disruption:low
Strategy:disable
include remove_vsftpd

class remove_vsftpd {
  package { 'vsftpd':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure vsftpd is removed
  package:
    name: vsftpd
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-CM-7.1(ii)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(1).1(v)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_vsftpd_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove vsftpd
#	   from the system, and may remove any packages
#	   that depend on vsftpd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "vsftpd" ; then

    dnf remove -y "vsftpd"

fi
Group   Web Server   Group contains 2 groups and 2 rules
[ref]   The web server is responsible for providing access to content via the HTTP protocol. Web servers represent a significant security risk because:

  • The HTTP port is commonly probed by malicious sources
  • Web server software is very complex, and includes a long history of vulnerabilities
  • The HTTP protocol is unencrypted and vulnerable to passive monitoring


The system's default web server software is Apache 2 and is provided in the RPM package httpd.
Group   Disable Apache if Possible   Group contains 1 rule
[ref]   If Apache was installed and activated, but the system does not need to act as a web server, then it should be disabled and removed from the system.

Rule   Uninstall httpd Package   [ref]

The httpd package can be removed with the following command:
$ sudo dnf erase httpd
Rationale:
If there is no need to make the web server software available, removing it provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_httpd_removed
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=httpd

Complexity:low
Disruption:low
Strategy:disable
include remove_httpd

class remove_httpd {
  package { 'httpd':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure httpd is removed
  package:
    name: httpd
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_httpd_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove httpd
#	   from the system, and may remove any packages
#	   that depend on httpd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "httpd" ; then

    dnf remove -y "httpd"

fi
Group   Disable NGINX if Possible   Group contains 1 rule
[ref]   If NGINX was installed and activated, but the system does not need to act as a web server, then it should be removed from the system.

Rule   Uninstall nginx Package   [ref]

The nginx package can be removed with the following command:
$ sudo dnf erase nginx
Rationale:
If there is no need to make the web server software available, removing it provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_nginx_removed
Identifiers and References

References:  BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3


Complexity:low
Disruption:low
Strategy:disable

package --remove=nginx

Complexity:low
Disruption:low
Strategy:disable
include remove_nginx

class remove_nginx {
  package { 'nginx':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure nginx is removed
  package:
    name: nginx
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_nginx_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove nginx
#	   from the system, and may remove any packages
#	   that depend on nginx. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "nginx" ; then

    dnf remove -y "nginx"

fi
Group   IMAP and POP3 Server   Group contains 2 groups and 2 rules
[ref]   Dovecot provides IMAP and POP3 services. It is not installed by default. The project page at http://www.dovecot.org contains more detailed information about Dovecot configuration.
Group   Disable Cyrus IMAP   Group contains 1 rule
[ref]   If the system does not need to operate as an IMAP or POP3 server, the Cyrus IMAP software should be removed.

Rule   Uninstall cyrus-imapd Package   [ref]

The cyrus-imapd package can be removed with the following command:
$ sudo dnf erase cyrus-imapd
Rationale:
If there is no need to make the cyrus-imapd software available, removing it provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_cyrus-imapd_removed
Identifiers and References

Complexity:low
Disruption:low
Strategy:disable

package --remove=cyrus-imapd

Complexity:low
Disruption:low
Strategy:disable
include remove_cyrus-imapd

class remove_cyrus-imapd {
  package { 'cyrus-imapd':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure cyrus-imapd is removed
  package:
    name: cyrus-imapd
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_cyrus-imapd_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove cyrus-imapd
#	   from the system, and may remove any packages
#	   that depend on cyrus-imapd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "cyrus-imapd" ; then

    dnf remove -y "cyrus-imapd"

fi
Group   Disable Dovecot   Group contains 1 rule
[ref]   If the system does not need to operate as an IMAP or POP3 server, the dovecot software should be disabled and removed.

Rule   Uninstall dovecot Package   [ref]

The dovecot package can be removed with the following command:
$ sudo dnf erase dovecot
Rationale:
If there is no need to make the Dovecot software available, removing it provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_dovecot_removed
Identifiers and References

Complexity:low
Disruption:low
Strategy:disable

package --remove=dovecot

Complexity:low
Disruption:low
Strategy:disable
include remove_dovecot

class remove_dovecot {
  package { 'dovecot':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure dovecot is removed
  package:
    name: dovecot
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_dovecot_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove dovecot
#	   from the system, and may remove any packages
#	   that depend on dovecot. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "dovecot" ; then

    dnf remove -y "dovecot"

fi
Group   Mail Server Software   Group contains 1 rule
[ref]   Mail servers are used to send and receive email over the network. Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious targets of network attack. Ensure that systems are not running MTAs unnecessarily, and configure needed MTAs as defensively as possible.

Very few systems at any site should be configured to directly receive email over the network. Users should instead use mail client programs to retrieve email from a central server that supports protocols such as IMAP or POP3. However, it is normal for most systems to be independently capable of sending email, for instance so that cron jobs can report output to an administrator. Most MTAs, including Postfix, support a submission-only mode in which mail can be sent from the local system to a central site MTA (or directly delivered to a local account), but the system still cannot receive mail directly over a network.

The alternatives program in Fedora permits selection of other mail server software (such as Sendmail), but Postfix is the default and is preferred. Postfix was coded with security in mind and can also be more effectively contained by SELinux as its modular design has resulted in separate processes performing specific actions. More information is available on its website, http://www.postfix.org.

Rule   Uninstall Sendmail Package   [ref]

Sendmail is not the default mail transfer agent and is not installed by default. The sendmail package can be removed with the following command:
$ sudo dnf erase sendmail
Rationale:
The sendmail software was not developed with security in mind and its design prevents it from being effectively contained by SELinux. Postfix should be used instead.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_sendmail_removed
Identifiers and References

References:  BP28(R1), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000381, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Strategy:disable

package --remove=sendmail

Complexity:low
Disruption:low
Strategy:disable
include remove_sendmail

class remove_sendmail {
  package { 'sendmail':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure sendmail is removed
  package:
    name: sendmail
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_sendmail_removed

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# CAUTION: This remediation script will remove sendmail
#	   from the system, and may remove any packages
#	   that depend on sendmail. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "sendmail" ; then

    dnf remove -y "sendmail"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   NFS and RPC   Group contains 4 groups and 2 rules
[ref]   The Network File System is a popular distributed filesystem for the Unix environment, and is very widely deployed. This section discusses the circumstances under which it is possible to disable NFS and its dependencies, and then details steps which should be taken to secure NFS's configuration. This section is relevant to systems operating as NFS clients, as well as to those operating as NFS servers.
Group   Disable All NFS Services if Possible   Group contains 1 group and 1 rule
[ref]   If there is not a reason for the system to operate as either an NFS client or an NFS server, follow all instructions in this section to disable subsystems required by NFS.
Warning:  The steps in this section will prevent a system from operating as either an NFS client or an NFS server. Only perform these steps on systems which do not need NFS at all.
Group   Disable Services Used Only by NFS   Group contains 1 rule
[ref]   If NFS is not needed, disable the NFS client daemons nfslock, rpcgssd, and rpcidmapd.

All of these daemons run with elevated privileges, and many listen for network connections. If they are not needed, they should be disabled to improve system security posture.

Rule   Disable rpcbind Service   [ref]

The rpcbind utility maps RPC services to the ports on which they listen. RPC processes notify rpcbind when they start, registering the ports they are listening on and the RPC program numbers they expect to serve. The rpcbind service redirects the client to the proper port number so it can communicate with the requested service. If the system does not require RPC (such as for NFS servers) then this service should be disabled. The rpcbind service can be disabled with the following command:
$ sudo systemctl mask --now rpcbind.service
Rationale:
If the system does not require rpc based services, it is recommended that rpcbind be disabled to reduce the attack surface.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_service_rpcbind_disabled
Identifiers and References

References:  2.2.4


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
      - name: rpcbind.service
        enabled: false
        mask: true
      - name: rpcbind.socket
        enabled: false
        mask: true


[customizations.services]
disabled = ["rpcbind"]

Complexity:low
Disruption:low
Strategy:enable
include disable_rpcbind

class disable_rpcbind {
  service {'rpcbind':
    enable => false,
    ensure => 'stopped',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Block Disable service rpcbind
  block:

  - name: Disable service rpcbind
    block:

    - name: Disable service rpcbind
      systemd:
        name: rpcbind.service
        enabled: 'no'
        state: stopped
        masked: 'yes'
    rescue:

    - name: Intentionally ignored previous 'Disable service rpcbind' failure, service
        was already disabled
      meta: noop
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

- name: Unit Socket Exists - rpcbind.socket
  command: systemctl list-unit-files rpcbind.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

- name: Disable socket rpcbind
  systemd:
    name: rpcbind.socket
    enabled: 'no'
    state: stopped
    masked: 'yes'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"rpcbind.socket" in socket_file_exists.stdout_lines[1]'
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_rpcbind_disabled

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" stop 'rpcbind.service'
"$SYSTEMCTL_EXEC" disable 'rpcbind.service'
"$SYSTEMCTL_EXEC" mask 'rpcbind.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files rpcbind.socket; then
    "$SYSTEMCTL_EXEC" stop 'rpcbind.socket'
    "$SYSTEMCTL_EXEC" mask 'rpcbind.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'rpcbind.service' || true

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Configure NFS Clients   Group contains 1 group and 1 rule
[ref]   The steps in this section are appropriate for systems which operate as NFS clients.
Group   Disable NFS Server Daemons   Group contains 1 rule
[ref]   There is no need to run the NFS server daemons nfs and rpcsvcgssd except on a small number of properly secured systems designated as NFS servers. Ensure that these daemons are turned off on clients.

Rule   Disable Network File System (nfs)   [ref]

The Network File System (NFS) service allows remote hosts to mount and interact with shared filesystems on the local system. If the local system is not designated as a NFS server then this service should be disabled. The nfs-server service can be disabled with the following command:
$ sudo systemctl mask --now nfs-server.service
Rationale:
Unnecessary services should be disabled to decrease the attack surface of the system.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_service_nfs_disabled
Identifiers and References

References:  11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    systemd:
      units:
      - name: nfs-server.service
        enabled: false
        mask: true
      - name: nfs-server.socket
        enabled: false
        mask: true


[customizations.services]
disabled = ["nfs-server"]

Complexity:low
Disruption:low
Strategy:enable
include disable_nfs-server

class disable_nfs-server {
  service {'nfs-server':
    enable => false,
    ensure => 'stopped',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Block Disable service nfs-server
  block:

  - name: Disable service nfs-server
    block:

    - name: Disable service nfs-server
      systemd:
        name: nfs-server.service
        enabled: 'no'
        state: stopped
        masked: 'yes'
    rescue:

    - name: Intentionally ignored previous 'Disable service nfs-server' failure, service
        was already disabled
      meta: noop
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_nfs_disabled
  - unknown_severity

- name: Unit Socket Exists - nfs-server.socket
  command: systemctl list-unit-files nfs-server.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_nfs_disabled
  - unknown_severity

- name: Disable socket nfs-server
  systemd:
    name: nfs-server.socket
    enabled: 'no'
    state: stopped
    masked: 'yes'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"nfs-server.socket" in socket_file_exists.stdout_lines[1]'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_nfs_disabled
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" stop 'nfs-server.service'
"$SYSTEMCTL_EXEC" disable 'nfs-server.service'
"$SYSTEMCTL_EXEC" mask 'nfs-server.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files nfs-server.socket; then
    "$SYSTEMCTL_EXEC" stop 'nfs-server.socket'
    "$SYSTEMCTL_EXEC" mask 'nfs-server.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'nfs-server.service' || true

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Time Protocol   Group contains 5 rules
[ref]   The Network Time Protocol is used to manage the system clock over a network. Computer clocks are not very accurate, so time will drift unpredictably on unmanaged systems. Central time protocols can be used both to ensure that time is consistent among a network of systems, and that their time is consistent with the outside world.

If every system on a network reliably reports the same time, then it is much easier to correlate log messages in case of an attack. In addition, a number of cryptographic protocols (such as Kerberos) use timestamps to prevent certain types of attacks. If your network does not have synchronized time, these protocols may be unreliable or even unusable.

Depending on the specifics of the network, global time accuracy may be just as important as local synchronization, or not very important at all. If your network is connected to the Internet, using a public timeserver (or one provided by your enterprise) provides globally accurate timestamps which may be essential in investigating or responding to an attack which originated outside of your network.

A typical network setup involves a small number of internal systems operating as NTP servers, and the remainder obtaining time information from those internal servers.

There is a choice between the daemons ntpd and chronyd, which are available from the repositories in the ntp and chrony packages respectively.

The default chronyd daemon can work well when external time references are only intermittently accesible, can perform well even when the network is congested for longer periods of time, can usually synchronize the clock faster and with better time accuracy, and quickly adapts to sudden changes in the rate of the clock, for example, due to changes in the temperature of the crystal oscillator. Chronyd should be considered for all systems which are frequently suspended or otherwise intermittently disconnected and reconnected to a network. Mobile and virtual systems for example.

The ntpd NTP daemon fully supports NTP protocol version 4 (RFC 5905), including broadcast, multicast, manycast clients and servers, and the orphan mode. It also supports extra authentication schemes based on public-key cryptography (RFC 5906). The NTP daemon (ntpd) should be considered for systems which are normally kept permanently on. Systems which are required to use broadcast or multicast IP, or to perform authentication of packets with the Autokey protocol, should consider using ntpd.

Refer to https://docs.fedoraproject.org/en-US/fedora/latest/system-administrators-guide/servers/Configuring_NTP_Using_the_chrony_Suite/ for more detailed comparison of features of chronyd and ntpd daemon features respectively, and for further guidance how to choose between the two NTP daemons.

The upstream manual pages at http://chrony.tuxfamily.org/manual.html for chronyd and http://www.ntp.org for ntpd provide additional information on the capabilities and configuration of each of the NTP daemons.

Rule   Disable chrony daemon from acting as server   [ref]

The port option in /etc/chrony.conf can be set to 0 to make chrony daemon to never open any listening port for server operation and to operate strictly in a client-only mode.
Rationale:
In order to prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_client_only
Identifiers and References

References:  CCI-000381, AU-8(1), AU-12(1), FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ %23%20Allow%20for%20extra%20configuration%20files.%20This%20is%20useful%0A%23%20for%20admins%20specifying%20their%20own%20NTP%20servers%0Ainclude%20/etc/chrony.d/%2A.conf%0A%0A%23%20Set%20chronyd%20as%20client-only.%0Aport%200%0A%0A%23%20Disable%20chronyc%20from%20the%20network%0Acmdport%200%0A%0A%23%20Record%20the%20rate%20at%20which%20the%20system%20clock%20gains/losses%20time.%0Adriftfile%20/var/lib/chrony/drift%0A%0A%23%20Allow%20the%20system%20clock%20to%20be%20stepped%20in%20the%20first%20three%20updates%0A%23%20if%20its%20offset%20is%20larger%20than%201%20second.%0Amakestep%201.0%203%0A%0A%23%20Enable%20kernel%20synchronization%20of%20the%20real-time%20clock%20%28RTC%29.%0Artcsync%0A%0A%23%20Enable%20hardware%20timestamping%20on%20all%20interfaces%20that%20support%20it.%0A%23hwtimestamp%20%2A%0A%0A%23%20Increase%20the%20minimum%20number%20of%20selectable%20sources%20required%20to%20adjust%0A%23%20the%20system%20clock.%0A%23minsources%202%0A%0A%23%20Allow%20NTP%20client%20access%20from%20local%20network.%0A%23allow%20192.168.0.0/16%0A%0A%23%20Serve%20time%20even%20if%20not%20synchronized%20to%20a%20time%20source.%0A%23local%20stratum%2010%0A%0A%23%20Require%20authentication%20%28nts%20or%20key%20option%29%20for%20all%20NTP%20sources.%0A%23authselectmode%20require%0A%0A%23%20Specify%20file%20containing%20keys%20for%20NTP%20authentication.%0Akeyfile%20/etc/chrony.keys%0A%0A%23%20Insert/delete%20leap%20seconds%20by%20slewing%20instead%20of%20stepping.%0A%23leapsecmode%20slew%0A%0A%23%20Get%20TAI-UTC%20offset%20and%20leap%20seconds%20from%20the%20system%20tz%20database.%0Aleapsectz%20right/UTC%0A%0A%23%20Specify%20directory%20for%20log%20files.%0Alogdir%20/var/log/chrony%0A%0A%23%20Select%20which%20information%20is%20logged.%0A%23log%20measurements%20statistics%20tracking }}
        mode: 420
        overwrite: true
        path: /etc/chrony.conf
      - contents:
          source: data:,
        mode: 420
        overwrite: true
        path: /etc/chrony.d/.mco-keep
      - contents:
          source: data:,{{ %23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20ntp%20server%0A%23%20%7B%7B.var_multiple_time_servers%7D%7D%20we%20have%20to%20put%20variable%20array%20name%20here%20for%20mutilines%20remediation%20%0A%7B%7B%24var_time_service_set_maxpoll%3A%3D.var_time_service_set_maxpoll%7D%7D%0A%7B%7Brange%20%24element%3A%3D.var_multiple_time_servers%7CtoArrayByComma%7D%7Dserver%20%7B%7B%24element%7D%7D%20minpoll%204%20maxpoll%20%7B%7B%24var_time_service_set_maxpoll%7D%7D%0A%7B%7Bend%7D%7D }}
        mode: 420
        overwrite: true
        path: /etc/chrony.d/ntp-server.conf

Complexity:low
Disruption:low
Strategy:restrict
- name: Disable chrony daemon from acting as server
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/chrony.conf
      create: false
      regexp: ^\s*port\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/chrony.conf
    lineinfile:
      path: /etc/chrony.conf
      create: false
      regexp: ^\s*port\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/chrony.conf
    lineinfile:
      path: /etc/chrony.conf
      create: true
      regexp: ^\s*port\s+
      line: port 0
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)
  - chronyd_client_only
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^port")

# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^port\\>" "/etc/chrony.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^port\\>.*/$escaped_formatted_output/gi" "/etc/chrony.conf"
else
    if [[ -s "/etc/chrony.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/chrony.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/chrony.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/chrony.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable network management of chrony daemon   [ref]

The cmdport option in /etc/chrony.conf can be set to 0 to stop chrony daemon from listening on the UDP port 323 for management connections made by chronyc.
Rationale:
Minimizing the exposure of the server functionality of the chrony daemon diminishes the attack surface.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_no_chronyc_network
Identifiers and References

References:  CCI-000381, CM-7(1), FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ %23%20Allow%20for%20extra%20configuration%20files.%20This%20is%20useful%0A%23%20for%20admins%20specifying%20their%20own%20NTP%20servers%0Ainclude%20/etc/chrony.d/%2A.conf%0A%0A%23%20Set%20chronyd%20as%20client-only.%0Aport%200%0A%0A%23%20Disable%20chronyc%20from%20the%20network%0Acmdport%200%0A%0A%23%20Record%20the%20rate%20at%20which%20the%20system%20clock%20gains/losses%20time.%0Adriftfile%20/var/lib/chrony/drift%0A%0A%23%20Allow%20the%20system%20clock%20to%20be%20stepped%20in%20the%20first%20three%20updates%0A%23%20if%20its%20offset%20is%20larger%20than%201%20second.%0Amakestep%201.0%203%0A%0A%23%20Enable%20kernel%20synchronization%20of%20the%20real-time%20clock%20%28RTC%29.%0Artcsync%0A%0A%23%20Enable%20hardware%20timestamping%20on%20all%20interfaces%20that%20support%20it.%0A%23hwtimestamp%20%2A%0A%0A%23%20Increase%20the%20minimum%20number%20of%20selectable%20sources%20required%20to%20adjust%0A%23%20the%20system%20clock.%0A%23minsources%202%0A%0A%23%20Allow%20NTP%20client%20access%20from%20local%20network.%0A%23allow%20192.168.0.0/16%0A%0A%23%20Serve%20time%20even%20if%20not%20synchronized%20to%20a%20time%20source.%0A%23local%20stratum%2010%0A%0A%23%20Require%20authentication%20%28nts%20or%20key%20option%29%20for%20all%20NTP%20sources.%0A%23authselectmode%20require%0A%0A%23%20Specify%20file%20containing%20keys%20for%20NTP%20authentication.%0Akeyfile%20/etc/chrony.keys%0A%0A%23%20Insert/delete%20leap%20seconds%20by%20slewing%20instead%20of%20stepping.%0A%23leapsecmode%20slew%0A%0A%23%20Get%20TAI-UTC%20offset%20and%20leap%20seconds%20from%20the%20system%20tz%20database.%0Aleapsectz%20right/UTC%0A%0A%23%20Specify%20directory%20for%20log%20files.%0Alogdir%20/var/log/chrony%0A%0A%23%20Select%20which%20information%20is%20logged.%0A%23log%20measurements%20statistics%20tracking }}
        mode: 420
        overwrite: true
        path: /etc/chrony.conf
      - contents:
          source: data:,
        mode: 420
        overwrite: true
        path: /etc/chrony.d/.mco-keep
      - contents:
          source: data:,{{ %23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20ntp%20server%0A%23%20%7B%7B.var_multiple_time_servers%7D%7D%20we%20have%20to%20put%20variable%20array%20name%20here%20for%20mutilines%20remediation%20%0A%7B%7B%24var_time_service_set_maxpoll%3A%3D.var_time_service_set_maxpoll%7D%7D%0A%7B%7Brange%20%24element%3A%3D.var_multiple_time_servers%7CtoArrayByComma%7D%7Dserver%20%7B%7B%24element%7D%7D%20minpoll%204%20maxpoll%20%7B%7B%24var_time_service_set_maxpoll%7D%7D%0A%7B%7Bend%7D%7D }}
        mode: 420
        overwrite: true
        path: /etc/chrony.d/ntp-server.conf

Complexity:low
Disruption:low
Strategy:restrict
- name: Disable network management of chrony daemon
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/chrony.conf
      create: false
      regexp: ^\s*cmdport\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/chrony.conf
    lineinfile:
      path: /etc/chrony.conf
      create: false
      regexp: ^\s*cmdport\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/chrony.conf
    lineinfile:
      path: /etc/chrony.conf
      create: true
      regexp: ^\s*cmdport\s+
      line: cmdport 0
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-7(1)
  - chronyd_no_chronyc_network
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^cmdport")

# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^cmdport\\>" "/etc/chrony.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^cmdport\\>.*/$escaped_formatted_output/gi" "/etc/chrony.conf"
else
    if [[ -s "/etc/chrony.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/chrony.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/chrony.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/chrony.conf"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Configure Time Service Maxpoll Interval   [ref]

The maxpoll should be configured to 10 in /etc/ntp.conf or /etc/chrony.conf to continuously poll time servers. To configure maxpoll in /etc/ntp.conf or /etc/chrony.conf add the following after each `server`, `pool` or `peer` entry:
maxpoll 10
to
server
directives. If using chrony any
pool
directives should be configured too. If no server or pool directives are configured, the rule evaluates to pass.
Rationale:
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints).
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_or_ntpd_set_maxpoll
Identifiers and References

References:  1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, CCI-001891, CCI-002046, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), AU-8(1)(b), AU-12(1), PR.PT-1, SRG-OS-000355-GPOS-00143, SRG-OS-000356-GPOS-00144, SRG-OS-000359-GPOS-00146


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,{{ %23%20Allow%20for%20extra%20configuration%20files.%20This%20is%20useful%0A%23%20for%20admins%20specifying%20their%20own%20NTP%20servers%0Ainclude%20/etc/chrony.d/%2A.conf%0A%0A%23%20Set%20chronyd%20as%20client-only.%0Aport%200%0A%0A%23%20Disable%20chronyc%20from%20the%20network%0Acmdport%200%0A%0A%23%20Record%20the%20rate%20at%20which%20the%20system%20clock%20gains/losses%20time.%0Adriftfile%20/var/lib/chrony/drift%0A%0A%23%20Allow%20the%20system%20clock%20to%20be%20stepped%20in%20the%20first%20three%20updates%0A%23%20if%20its%20offset%20is%20larger%20than%201%20second.%0Amakestep%201.0%203%0A%0A%23%20Enable%20kernel%20synchronization%20of%20the%20real-time%20clock%20%28RTC%29.%0Artcsync%0A%0A%23%20Enable%20hardware%20timestamping%20on%20all%20interfaces%20that%20support%20it.%0A%23hwtimestamp%20%2A%0A%0A%23%20Increase%20the%20minimum%20number%20of%20selectable%20sources%20required%20to%20adjust%0A%23%20the%20system%20clock.%0A%23minsources%202%0A%0A%23%20Allow%20NTP%20client%20access%20from%20local%20network.%0A%23allow%20192.168.0.0/16%0A%0A%23%20Serve%20time%20even%20if%20not%20synchronized%20to%20a%20time%20source.%0A%23local%20stratum%2010%0A%0A%23%20Require%20authentication%20%28nts%20or%20key%20option%29%20for%20all%20NTP%20sources.%0A%23authselectmode%20require%0A%0A%23%20Specify%20file%20containing%20keys%20for%20NTP%20authentication.%0Akeyfile%20/etc/chrony.keys%0A%0A%23%20Insert/delete%20leap%20seconds%20by%20slewing%20instead%20of%20stepping.%0A%23leapsecmode%20slew%0A%0A%23%20Get%20TAI-UTC%20offset%20and%20leap%20seconds%20from%20the%20system%20tz%20database.%0Aleapsectz%20right/UTC%0A%0A%23%20Specify%20directory%20for%20log%20files.%0Alogdir%20/var/log/chrony%0A%0A%23%20Select%20which%20information%20is%20logged.%0A%23log%20measurements%20statistics%20tracking }}
        mode: 420
        overwrite: true
        path: /etc/chrony.conf
      - contents:
          source: data:,
        mode: 420
        overwrite: true
        path: /etc/chrony.d/.mco-keep
      - contents:
          source: data:,{{ %23%0A%23%20This%20file%20controls%20the%20configuration%20of%20the%20ntp%20server%0A%23%20%7B%7B.var_multiple_time_servers%7D%7D%20we%20have%20to%20put%20variable%20array%20name%20here%20for%20mutilines%20remediation%20%0A%7B%7B%24var_time_service_set_maxpoll%3A%3D.var_time_service_set_maxpoll%7D%7D%0A%7B%7Brange%20%24element%3A%3D.var_multiple_time_servers%7CtoArrayByComma%7D%7Dserver%20%7B%7B%24element%7D%7D%20minpoll%204%20maxpoll%20%7B%7B%24var_time_service_set_maxpoll%7D%7D%0A%7B%7Bend%7D%7D }}
        mode: 420
        overwrite: true
        path: /etc/chrony.d/ntp-server.conf

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_time_service_set_maxpoll # promote to variable
  set_fact:
    var_time_service_set_maxpoll: !!str 10
  tags:
    - always

- name: Check that /etc/ntp.conf exist
  stat:
    path: /etc/ntp.conf
  register: ntp_conf_exist_result
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Update the maxpoll values in /etc/ntp.conf
  replace:
    path: /etc/ntp.conf
    regexp: ^(server.*maxpoll)[ ]+[0-9]+(.*)$
    replace: \1 {{ var_time_service_set_maxpoll }}\2
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  - ntp_conf_exist_result.stat.exists
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set the maxpoll values in /etc/ntp.conf
  replace:
    path: /etc/ntp.conf
    regexp: (^server\s+((?!maxpoll).)*)$
    replace: \1 maxpoll {{ var_time_service_set_maxpoll }}\n
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  - ntp_conf_exist_result.stat.exists
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check that /etc/chrony.conf exist
  stat:
    path: /etc/chrony.conf
  register: chrony_conf_exist_result
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Get get conf files from /etc/chrony.conf
  shell: |
    set -o pipefail
    CHRONY_NAME=/etc/chrony.conf
    CHRONY_PATH=${CHRONY_NAME%%.*}
    find ${CHRONY_PATH}.* -type f -name '*.conf'
  register: update_chrony_files
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  - chrony_conf_exist_result.stat.exists
  changed_when: false
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Update the maxpoll values in /etc/chrony.conf
  replace:
    path: '{{ item }}'
    regexp: ^((?:server|pool|peer).*maxpoll)[ ]+[0-9]+(.*)$
    replace: \1 {{ var_time_service_set_maxpoll }}\2
  loop: '{{ update_chrony_files.stdout_lines|list|flatten|unique }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  - chrony_conf_exist_result.stat.exists
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set the maxpoll values in /etc/chrony.conf
  replace:
    path: '{{ item }}'
    regexp: (^(?:server|pool|peer)\s+((?!maxpoll).)*)$
    replace: \1 maxpoll {{ var_time_service_set_maxpoll }}\n
  loop: '{{ update_chrony_files.stdout_lines|list|flatten|unique }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
  - chrony_conf_exist_result.stat.exists
  tags:
  - NIST-800-53-AU-12(1)
  - NIST-800-53-AU-8(1)(b)
  - NIST-800-53-CM-6(a)
  - chronyd_or_ntpd_set_maxpoll
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { ( rpm --quiet -q chrony || rpm --quiet -q ntp ); }; then

var_time_service_set_maxpoll='10'




pof="/usr/sbin/pidof"


CONFIG_FILES="/etc/ntp.conf"
$pof ntpd || {
    CHRONY_NAME=/etc/chrony.conf
    CHRONY_PATH=${CHRONY_NAME%%.*}
    CONFIG_FILES=$(find ${CHRONY_PATH}.* -type f -name '*.conf')
}

# get list of ntp files

for config_file in $CONFIG_FILES; do
    # Set maxpoll values to var_time_service_set_maxpoll
    sed -i "s/^\(\(server\|pool\|peer\).*maxpoll\) [0-9][0-9]*\(.*\)$/\1 $var_time_service_set_maxpoll \3/" "$config_file"
done




for config_file in $CONFIG_FILES; do
    # Add maxpoll to server, pool or peer entries without maxpoll
    grep "^\(server\|pool\|peer\)" "$config_file" | grep -v maxpoll | while read -r line ; do
        sed -i "s/$line/& maxpoll $var_time_service_set_maxpoll/" "$config_file"
    done
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure that chronyd is running under chrony user account   [ref]

chrony is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at http://chrony.tuxfamily.org/. Chrony can be configured to be a client and/or a server. To ensure that chronyd is running under chrony user account, remove any -u ... option from OPTIONS other than -u chrony, as chrony is run under its own user by default. This recommendation only applies if chrony is in use on the system.
Rationale:
If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_run_as_chrony_user
Identifiers and References

Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - chronyd_run_as_chrony_user
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Detect if file /etc/sysconfig/chronyd is not empty or missing
  find:
    path: /etc/sysconfig/
    patterns: chronyd
    contains: ^([\s]*OPTIONS=["]?[^"]*)("?)
  register: chronyd_file
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"chrony" in ansible_facts.packages'
  tags:
  - chronyd_run_as_chrony_user
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Remove any previous configuration of user used to run chronyd process
  replace:
    path: /etc/sysconfig/chronyd
    regexp: \s*-u\s*\w+\s*
    replace: ' '
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"chrony" in ansible_facts.packages'
  - chronyd_file is defined and chronyd_file.matched > 0
  tags:
  - chronyd_run_as_chrony_user
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q chrony; }; then

if grep -q 'OPTIONS=.*' /etc/sysconfig/chronyd; then
	# trying to solve cases where the parameter after OPTIONS
	#may or may not be enclosed in quotes
	sed -i -E -e 's/\s*-u\s*\w+\s*/ /' -e 's/^([\s]*OPTIONS=["]?[^"]*)("?)/\1\2/' /etc/sysconfig/chronyd
fi

if grep -q 'OPTIONS=.*' /etc/sysconfig/chronyd; then
	# trying to solve cases where the parameter after OPTIONS
	#may or may not be enclosed in quotes
	sed -i -E -e 's/\s*-u\s*\w+\s*/ /' -e 's/^([\s]*OPTIONS=["]?[^"]*)("?)/\1 -u chrony\2/' /etc/sysconfig/chronyd
else
	echo 'OPTIONS="-u chrony"' >> /etc/sysconfig/chronyd
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   A remote time server for Chrony is configured   [ref]

Chrony is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at http://chrony.tuxfamily.org/. Chrony can be configured to be a client and/or a server. Add or edit server or pool lines to /etc/chrony.conf as appropriate:
server <remote-server>
Multiple servers may be configured.
Rationale:
If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_chronyd_specify_remote_server
Identifiers and References

References:  BP28(R43), CCI-000160, CCI-001891, 0988, 1405, CM-6(a), AU-8(1)(a), Req-10.4.3, 10.6.2


Complexity:low
Disruption:low
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.3
  - PCI-DSSv4-10.6.2
  - chronyd_specify_remote_server
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_multiple_time_servers # promote to variable
  set_fact:
    var_multiple_time_servers: !!str 0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org
  tags:
    - always

- name: Detect if chrony is already configured with pools or servers
  find:
    path: /etc
    patterns: chrony.conf
    contains: ^[\s]*(?:server|pool)[\s]+[\w]+
  register: chrony_servers
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"chrony" in ansible_facts.packages'
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.3
  - PCI-DSSv4-10.6.2
  - chronyd_specify_remote_server
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure remote time servers
  lineinfile:
    path: /etc/chrony.conf
    line: server {{ item }}
    state: present
    create: true
  loop: '{{ var_multiple_time_servers.split(",") }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"chrony" in ansible_facts.packages'
  - chrony_servers.matched == 0
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4.3
  - PCI-DSSv4-10.6.2
  - chronyd_specify_remote_server
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q chrony; }; then

var_multiple_time_servers='0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org'


config_file="/etc/chrony.conf"

if ! grep -q '^[[:space:]]*\(server\|pool\)[[:space:]]\+[[:graph:]]\+' "$config_file" ; then
  if ! grep -q '#[[:space:]]*server' "$config_file" ; then
    for server in $(echo "$var_multiple_time_servers" | tr ',' '\n') ; do
      printf '\nserver %s' "$server" >> "$config_file"
    done
  else
    sed -i 's/#[ \t]*server/server/g' "$config_file"
  fi
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Obsolete Services   Group contains 6 groups and 12 rules
[ref]   This section discusses a number of network-visible services which have historically caused problems for system security, and for which disabling or severely limiting the service has been the best available guidance for some time. As a result of this, many of these services are not installed as part of Fedora by default.

Organizations which are running these services should switch to more secure equivalents as soon as possible. If it remains absolutely necessary to run one of these services for legacy reasons, care should be taken to restrict the service as much as possible, for instance by configuring host firewall software such as iptables to restrict access to the vulnerable service to only those remote hosts which have a known need to use it.
Group   Xinetd   Group contains 1 rule
[ref]   The xinetd service acts as a dedicated listener for some network services (mostly, obsolete ones) and can be used to provide access controls and perform some logging. It has been largely obsoleted by other features, and it is not installed by default. The older Inetd service is not even available as part of Fedora.

Rule   Uninstall xinetd Package   [ref]

The xinetd package can be removed with the following command:
$ sudo dnf erase xinetd
Rationale:
Removing the xinetd package decreases the risk of the xinetd service's accidental (or intentional) activation.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_xinetd_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000305, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=xinetd

Complexity:low
Disruption:low
Strategy:disable
include remove_xinetd

class remove_xinetd {
  package { 'xinetd':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure xinetd is removed
  package:
    name: xinetd
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_xinetd_removed

Complexity:low
Disruption:low
Strategy:disable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

# CAUTION: This remediation script will remove xinetd
#	   from the system, and may remove any packages
#	   that depend on xinetd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "xinetd" ; then

    dnf remove -y "xinetd"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   NIS   Group contains 2 rules
[ref]   The Network Information Service (NIS), also known as 'Yellow Pages' (YP), and its successor NIS+ have been made obsolete by Kerberos, LDAP, and other modern centralized authentication services. NIS should not be used because it suffers from security problems inherent in its design, such as inadequate protection of important authentication information.

Rule   Remove NIS Client   [ref]

The Network Information Service (NIS), formerly known as Yellow Pages, is a client-server directory service protocol used to distribute system configuration files. The NIS client (ypbind) was used to bind a system to an NIS server and receive the distributed configuration files.
Rationale:
The NIS service is inherently an insecure system that has been vulnerable to DOS attacks, buffer overflows and has poor authentication for querying NIS maps. NIS generally has been replaced by such protocols as Lightweight Directory Access Protocol (LDAP). It is recommended that the service be removed.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_ypbind_removed
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=ypbind

Complexity:low
Disruption:low
Strategy:disable
include remove_ypbind

class remove_ypbind {
  package { 'ypbind':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure ypbind is removed
  package:
    name: ypbind
    state: absent
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_ypbind_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove ypbind
#	   from the system, and may remove any packages
#	   that depend on ypbind. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "ypbind" ; then

    dnf remove -y "ypbind"

fi

Rule   Uninstall ypserv Package   [ref]

The ypserv package can be removed with the following command:
$ sudo dnf erase ypserv
Rationale:
The NIS service provides an unencrypted authentication service which does not provide for the confidentiality and integrity of user passwords or the remote session. Removing the ypserv package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_ypserv_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, 2.2.4, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Strategy:disable

package --remove=ypserv

Complexity:low
Disruption:low
Strategy:disable
include remove_ypserv

class remove_ypserv {
  package { 'ypserv':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure ypserv is removed
  package:
    name: ypserv
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-IA-5(1)(c)
  - PCI-DSS-Req-2.2.2
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_ypserv_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove ypserv
#	   from the system, and may remove any packages
#	   that depend on ypserv. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "ypserv" ; then

    dnf remove -y "ypserv"

fi
Group   Rlogin, Rsh, and Rexec   Group contains 2 rules
[ref]   The Berkeley r-commands are legacy services which allow cleartext remote access and have an insecure trust model.

Rule   Uninstall rsh-server Package   [ref]

The rsh-server package can be removed with the following command:
$ sudo dnf erase rsh-server
Rationale:
The rsh-server service provides unencrypted remote access service which does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. If a privileged user were to login using this service, the privileged user password could be compromised. The rsh-server package provides several obsolete and insecure network services. Removing it decreases the risk of those services' accidental (or intentional) activation.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_rsh-server_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Strategy:disable

package --remove=rsh-server

Complexity:low
Disruption:low
Strategy:disable
include remove_rsh-server

class remove_rsh-server {
  package { 'rsh-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure rsh-server is removed
  package:
    name: rsh-server
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-IA-5(1)(c)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_rsh-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove rsh-server
#	   from the system, and may remove any packages
#	   that depend on rsh-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "rsh-server" ; then

    dnf remove -y "rsh-server"

fi

Rule   Uninstall rsh Package   [ref]

The rsh package contains the client commands for the rsh services
Rationale:
These legacy clients contain numerous security exposures and have been replaced with the more secure SSH package. Even if the server is removed, it is best to ensure the clients are also removed to prevent users from inadvertently attempting to use these commands and therefore exposing their credentials. Note that removing the rsh package removes the clients for rsh,rcp, and rlogin.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_rsh_removed
Identifiers and References

References:  BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=rsh

Complexity:low
Disruption:low
Strategy:disable
include remove_rsh

class remove_rsh {
  package { 'rsh':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure rsh is removed
  package:
    name: rsh
    state: absent
  tags:
  - NIST-800-171-3.1.13
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_rsh_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove rsh
#	   from the system, and may remove any packages
#	   that depend on rsh. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "rsh" ; then

    dnf remove -y "rsh"

fi
Group   Chat/Messaging Services   Group contains 2 rules
[ref]   The talk software makes it possible for users to send and receive messages across systems through a terminal session.

Rule   Uninstall talk-server Package   [ref]

The talk-server package can be removed with the following command:
 $ sudo dnf erase talk-server
Rationale:
The talk software presents a security risk as it uses unencrypted protocols for communications. Removing the talk-server package decreases the risk of the accidental (or intentional) activation of talk services.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_talk-server_removed
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)


Complexity:low
Disruption:low
Strategy:disable

package --remove=talk-server

Complexity:low
Disruption:low
Strategy:disable
include remove_talk-server

class remove_talk-server {
  package { 'talk-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure talk-server is removed
  package:
    name: talk-server
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_talk-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove talk-server
#	   from the system, and may remove any packages
#	   that depend on talk-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "talk-server" ; then

    dnf remove -y "talk-server"

fi

Rule   Uninstall talk Package   [ref]

The talk package contains the client program for the Internet talk protocol, which allows the user to chat with other users on different systems. Talk is a communication program which copies lines from one terminal to the terminal of another user. The talk package can be removed with the following command:
$ sudo dnf erase talk
Rationale:
The talk software presents a security risk as it uses unencrypted protocols for communications. Removing the talk package decreases the risk of the accidental (or intentional) activation of talk client program.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_talk_removed
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=talk

Complexity:low
Disruption:low
Strategy:disable
include remove_talk

class remove_talk {
  package { 'talk':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure talk is removed
  package:
    name: talk
    state: absent
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_talk_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove talk
#	   from the system, and may remove any packages
#	   that depend on talk. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "talk" ; then

    dnf remove -y "talk"

fi
Group   Telnet   Group contains 2 rules
[ref]   The telnet protocol does not provide confidentiality or integrity for information transmitted on the network. This includes authentication information such as passwords. Organizations which use telnet should be actively working to migrate to a more secure protocol.

Rule   Uninstall telnet-server Package   [ref]

The telnet-server package can be removed with the following command:
$ sudo dnf erase telnet-server
Rationale:
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore may remain unsecure. They increase the risk to the platform by providing additional attack vectors.
The telnet service provides an unencrypted remote access service which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised.
Removing the telnet-server package decreases the risk of the telnet service's accidental (or intentional) activation.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_telnet-server_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, 2.2.4, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Strategy:disable

package --remove=telnet-server

Complexity:low
Disruption:low
Strategy:disable
include remove_telnet-server

class remove_telnet-server {
  package { 'telnet-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure telnet-server is removed
  package:
    name: telnet-server
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-2.2.2
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_telnet-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove telnet-server
#	   from the system, and may remove any packages
#	   that depend on telnet-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "telnet-server" ; then

    dnf remove -y "telnet-server"

fi

Rule   Remove telnet Clients   [ref]

The telnet client allows users to start connections to other systems via the telnet protocol.
Rationale:
The telnet protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The ssh package provides an encrypted session and stronger security and is included in Fedora.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_telnet_removed
Identifiers and References

References:  BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=telnet

Complexity:low
Disruption:low
Strategy:disable
include remove_telnet

class remove_telnet {
  package { 'telnet':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure telnet is removed
  package:
    name: telnet
    state: absent
  tags:
  - NIST-800-171-3.1.13
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_telnet_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove telnet
#	   from the system, and may remove any packages
#	   that depend on telnet. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "telnet" ; then

    dnf remove -y "telnet"

fi
Group   TFTP Server   Group contains 2 rules
[ref]   TFTP is a lightweight version of the FTP protocol which has traditionally been used to configure networking equipment. However, TFTP provides little security, and modern versions of networking operating systems frequently support configuration via SSH or other more secure protocols. A TFTP server should be run only if no more secure method of supporting existing equipment can be found.

Rule   Uninstall tftp-server Package   [ref]

The tftp-server package can be removed with the following command:
 $ sudo dnf erase tftp-server
Rationale:
Removing the tftp-server package decreases the risk of the accidental (or intentional) activation of tftp services.

If TFTP is required for operational support (such as transmission of router configurations), its use must be documented with the Information Systems Securty Manager (ISSM), restricted to only authorized personnel, and have access control rules established.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_tftp-server_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000318, CCI-000366, CCI-000368, CCI-001812, CCI-001813, CCI-001814, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:disable

package --remove=tftp-server

Complexity:low
Disruption:low
Strategy:disable
include remove_tftp-server

class remove_tftp-server {
  package { 'tftp-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure tftp-server is removed
  package:
    name: tftp-server
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_tftp-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove tftp-server
#	   from the system, and may remove any packages
#	   that depend on tftp-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "tftp-server" ; then

    dnf remove -y "tftp-server"

fi

Rule   Remove tftp Daemon   [ref]

Trivial File Transfer Protocol (TFTP) is a simple file transfer protocol, typically used to automatically transfer configuration or boot files between systems. TFTP does not support authentication and can be easily hacked. The package tftp is a client program that allows for connections to a tftp server.
Rationale:
It is recommended that TFTP be removed, unless there is a specific need for TFTP (such as a boot server). In that case, use extreme caution when configuring the services.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_tftp_removed
Identifiers and References

References:  BP28(R1)


Complexity:low
Disruption:low
Strategy:disable

package --remove=tftp

Complexity:low
Disruption:low
Strategy:disable
include remove_tftp

class remove_tftp {
  package { 'tftp':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure tftp is removed
  package:
    name: tftp
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_tftp_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove tftp
#	   from the system, and may remove any packages
#	   that depend on tftp. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "tftp" ; then

    dnf remove -y "tftp"

fi

Rule   Uninstall rsync Package   [ref]

The rsyncd service can be used to synchronize files between systems over network links. The rsync package can be removed with the following command:
$ sudo dnf erase rsync
Rationale:
The rsyncd service presents a security risk as it uses unencrypted protocols for communication.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_rsync_removed
Identifiers and References

Complexity:low
Disruption:low
Strategy:disable

package --remove=rsync

Complexity:low
Disruption:low
Strategy:disable
include remove_rsync

class remove_rsync {
  package { 'rsync':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure rsync is removed
  package:
    name: rsync
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_rsync_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove rsync
#	   from the system, and may remove any packages
#	   that depend on rsync. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "rsync" ; then

    dnf remove -y "rsync"

fi
Group   Proxy Server   Group contains 1 group and 1 rule
[ref]   A proxy server is a very desirable target for a potential adversary because much (or all) sensitive data for a given infrastructure may flow through it. Therefore, if one is required, the system acting as a proxy server should be dedicated to that purpose alone and be stored in a physically secure location. The system's default proxy server software is Squid, and provided in an RPM package of the same name.
Group   Disable Squid if Possible   Group contains 1 rule
[ref]   If Squid was installed and activated, but the system does not need to act as a proxy server, then it should be disabled and removed.

Rule   Uninstall squid Package   [ref]

The squid package can be removed with the following command:
 $ sudo dnf erase squid
Rationale:
If there is no need to make the proxy server software available, removing it provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_squid_removed
Identifiers and References

Complexity:low
Disruption:low
Strategy:disable

package --remove=squid

Complexity:low
Disruption:low
Strategy:disable
include remove_squid

class remove_squid {
  package { 'squid':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure squid is removed
  package:
    name: squid
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_squid_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove squid
#	   from the system, and may remove any packages
#	   that depend on squid. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "squid" ; then

    dnf remove -y "squid"

fi
Group   Samba(SMB) Microsoft Windows File Sharing Server   Group contains 1 group and 1 rule
[ref]   When properly configured, the Samba service allows Linux systems to provide file and print sharing to Microsoft Windows systems. There are two software packages that provide Samba support. The first, samba-client, provides a series of command line tools that enable a client system to access Samba shares. The second, simply labeled samba, provides the Samba service. It is this second package that allows a Linux system to act as an Active Directory server, a domain controller, or as a domain member. Only the samba-client package is installed by default.
Group   Disable Samba if Possible   Group contains 1 rule
[ref]   Even after the Samba server package has been installed, it will remain disabled. Do not enable this service unless it is absolutely necessary to provide Microsoft Windows file and print sharing functionality.

Rule   Uninstall Samba Package   [ref]

The samba package can be removed with the following command:
 $ sudo dnf erase samba
Rationale:
If there is no need to make the Samba software available, removing it provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_samba_removed
Identifiers and References

References:  2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=samba

Complexity:low
Disruption:low
Strategy:disable
include remove_samba

class remove_samba {
  package { 'samba':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure samba is removed
  package:
    name: samba
    state: absent
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_samba_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove samba
#	   from the system, and may remove any packages
#	   that depend on samba. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "samba" ; then

    dnf remove -y "samba"

fi
Group   SNMP Server   Group contains 1 group and 1 rule
[ref]   The Simple Network Management Protocol allows administrators to monitor the state of network devices, including computers. Older versions of SNMP were well-known for weak security, such as plaintext transmission of the community string (used for authentication) and usage of easily-guessable choices for the community string.
Group   Disable SNMP Server if Possible   Group contains 1 rule
[ref]   The system includes an SNMP daemon that allows for its remote monitoring, though it not installed by default. If it was installed and activated but is not needed, the software should be disabled and removed.

Rule   Uninstall net-snmp Package   [ref]

The net-snmp package provides the snmpd service. The net-snmp package can be removed with the following command:
$ sudo dnf erase net-snmp
Rationale:
If there is no need to run SNMP server software, removing the package provides a safeguard against its activation.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_net-snmp_removed
Identifiers and References

References:  2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=net-snmp

Complexity:low
Disruption:low
Strategy:disable
include remove_net-snmp

class remove_net-snmp {
  package { 'net-snmp':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure net-snmp is removed
  package:
    name: net-snmp
    state: absent
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_net-snmp_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove net-snmp
#	   from the system, and may remove any packages
#	   that depend on net-snmp. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "net-snmp" ; then

    dnf remove -y "net-snmp"

fi
Group   SSH Server   Group contains 1 group and 27 rules
[ref]   The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, through the use of public key cryptography. The implementation included with the system is called OpenSSH, and more detailed documentation is available from its website, https://www.openssh.com. Its server program is called sshd and provided by the RPM package openssh-server.
Group   Configure OpenSSH Server if Necessary   Group contains 22 rules
[ref]   If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file /etc/ssh/sshd_config. The following recommendations can be applied to this file. See the sshd_config(5) man page for more detailed information.

Rule   Set SSH Client Alive Count Max to zero   [ref]

The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. To ensure the SSH timeout occurs precisely when the ClientAliveInterval is set, set the ClientAliveCountMax to value of 0 in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
Rationale:
This ensures a user login will be terminated as soon as the ClientAliveInterval is reached.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_keepalive_0
Identifiers and References

References:  1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, 8.2.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109


Complexity:low
Disruption:low
Strategy:restrict
- name: Set SSH Client Alive Count Max to zero
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter ClientAliveCountMax is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      create: true
      regexp: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
      line: ClientAliveCountMax 0
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_keepalive_0

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "ClientAliveCountMax 0" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    printf '%s\n' "ClientAliveCountMax 0" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH Client Alive Count Max   [ref]

The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. For SSH earlier than v8.2, a ClientAliveCountMax value of 0 causes a timeout precisely when the ClientAliveInterval is set. Starting with v8.2, a value of 0 disables the timeout functionality completely. If the option is set to a number greater than 0, then the session will be disconnected after ClientAliveInterval * ClientAliveCountMax seconds without receiving a keep alive message.
Rationale:
This ensures a user login will be terminated as soon as the ClientAliveInterval is reached.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_keepalive
Identifiers and References

References:  BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, 8.2.8, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_sshd_set_keepalive # promote to variable
  set_fact:
    var_sshd_set_keepalive: !!str 0
  tags:
    - always

- name: Set SSH Client Alive Count Max
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveCountMax\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveCountMax\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveCountMax\s+
      line: ClientAliveCountMax {{ var_sshd_set_keepalive }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_keepalive

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_sshd_set_keepalive='0'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH Client Alive Interval   [ref]

SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out.

To set this timeout interval, edit the following line in /etc/ssh/sshd_config as follows:
ClientAliveInterval 900


The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600.

If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.
Warning:  SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration.
Warning:  Following conditions may prevent the SSH session to time out:
  • Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
  • Any scp or sftp activity by the same user to the host resets the timeout.
Rationale:
Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_idle_timeout
Identifiers and References

References:  BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, 8.2.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value sshd_idle_timeout_value # promote to variable
  set_fact:
    sshd_idle_timeout_value: !!str 900
  tags:
    - always

- name: Set SSH Client Alive Interval
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveInterval\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveInterval\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveInterval\s+
      line: ClientAliveInterval {{ sshd_idle_timeout_value }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_idle_timeout

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

sshd_idle_timeout_value='900'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Host-Based Authentication   [ref]

SSH's cryptographic host-based authentication is more secure than .rhosts authentication. However, it is not recommended that hosts unilaterally trust one another, even within an organization.
The default SSH configuration disables host-based authentication. The appropriate configuration is used if no value is set for HostbasedAuthentication.
To explicitly disable host-based authentication, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
HostbasedAuthentication no
Rationale:
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_disable_host_auth
Identifiers and References

References:  11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-3, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_UAU.1, 8.3.1, SRG-OS-000480-GPOS-00229


---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,%23%09%24OpenBSD%3A%20sshd_config%2Cv%201.103%202018%2F04%2F09%2020%3A41%3A22%20tj%20Exp%20%24%0A%0A%23%20This%20is%20the%20sshd%20server%20system-wide%20configuration%20file.%20%20See%0A%23%20sshd_config%285%29%20for%20more%20information.%0A%0A%23%20This%20sshd%20was%20compiled%20with%20PATH%3D%2Fusr%2Flocal%2Fbin%3A%2Fusr%2Fbin%3A%2Fusr%2Flocal%2Fsbin%3A%2Fusr%2Fsbin%0A%0A%23%20The%20strategy%20used%20for%20options%20in%20the%20default%20sshd_config%20shipped%20with%0A%23%20OpenSSH%20is%20to%20specify%20options%20with%20their%20default%20value%20where%0A%23%20possible%2C%20but%20leave%20them%20commented.%20%20Uncommented%20options%20override%20the%0A%23%20default%20value.%0A%0A%23%20If%20you%20want%20to%20change%20the%20port%20on%20a%20SELinux%20system%2C%20you%20have%20to%20tell%0A%23%20SELinux%20about%20this%20change.%0A%23%20semanage%20port%20-a%20-t%20ssh_port_t%20-p%20tcp%20%23PORTNUMBER%0A%23%0A%23Port%2022%0A%23AddressFamily%20any%0A%23ListenAddress%200.0.0.0%0A%23ListenAddress%20%3A%3A%0A%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_rsa_key%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_ecdsa_key%0AHostKey%20%2Fetc%2Fssh%2Fssh_host_ed25519_key%0A%0A%23%20Ciphers%20and%20keying%0ARekeyLimit%20512M%201h%0A%0A%23%20System-wide%20Crypto%20policy%3A%0A%23%20This%20system%20is%20following%20system-wide%20crypto%20policy.%20The%20changes%20to%0A%23%20Ciphers%2C%20MACs%2C%20KexAlgoritms%20and%20GSSAPIKexAlgorithsm%20will%20not%20have%20any%0A%23%20effect%20here.%20They%20will%20be%20overridden%20by%20command-line%20options%20passed%20on%0A%23%20the%20server%20start%20up.%0A%23%20To%20opt%20out%2C%20uncomment%20a%20line%20with%20redefinition%20of%20%20CRYPTO_POLICY%3D%0A%23%20variable%20in%20%20%2Fetc%2Fsysconfig%2Fsshd%20%20to%20overwrite%20the%20policy.%0A%23%20For%20more%20information%2C%20see%20manual%20page%20for%20update-crypto-policies%288%29.%0A%0A%23%20Logging%0A%23SyslogFacility%20AUTH%0ASyslogFacility%20AUTHPRIV%0A%23LogLevel%20INFO%0A%0A%23%20Authentication%3A%0A%0A%23LoginGraceTime%202m%0APermitRootLogin%20no%0AStrictModes%20yes%0A%23MaxAuthTries%206%0A%23MaxSessions%2010%0A%0APubkeyAuthentication%20yes%0A%0A%23%20The%20default%20is%20to%20check%20both%20.ssh%2Fauthorized_keys%20and%20.ssh%2Fauthorized_keys2%0A%23%20but%20this%20is%20overridden%20so%20installations%20will%20only%20check%20.ssh%2Fauthorized_keys%0AAuthorizedKeysFile%09.ssh%2Fauthorized_keys%0A%0A%23AuthorizedPrincipalsFile%20none%0A%0A%23AuthorizedKeysCommand%20none%0A%23AuthorizedKeysCommandUser%20nobody%0A%0A%23%20For%20this%20to%20work%20you%20will%20also%20need%20host%20keys%20in%20%2Fetc%2Fssh%2Fssh_known_hosts%0AHostbasedAuthentication%20no%0A%23%20Change%20to%20yes%20if%20you%20don%27t%20trust%20~%2F.ssh%2Fknown_hosts%20for%0A%23%20HostbasedAuthentication%0AIgnoreUserKnownHosts%20yes%0A%23%20Don%27t%20read%20the%20user%27s%20~%2F.rhosts%20and%20~%2F.shosts%20files%0AIgnoreRhosts%20yes%0A%0A%23%20To%20disable%20tunneled%20clear%20text%20passwords%2C%20change%20to%20no%20here%21%0A%23PasswordAuthentication%20yes%0APermitEmptyPasswords%20no%0APasswordAuthentication%20no%0A%0A%23%20Change%20to%20no%20to%20disable%20s%2Fkey%20passwords%0A%23ChallengeResponseAuthentication%20yes%0AChallengeResponseAuthentication%20no%0A%0A%23%20Kerberos%20options%0AKerberosAuthentication%20no%0A%23KerberosOrLocalPasswd%20yes%0A%23KerberosTicketCleanup%20yes%0A%23KerberosGetAFSToken%20no%0A%23KerberosUseKuserok%20yes%0A%0A%23%20GSSAPI%20options%0AGSSAPIAuthentication%20no%0AGSSAPICleanupCredentials%20no%0A%23GSSAPIStrictAcceptorCheck%20yes%0A%23GSSAPIKeyExchange%20no%0A%23GSSAPIEnablek5users%20no%0A%0A%23%20Set%20this%20to%20%27yes%27%20to%20enable%20PAM%20authentication%2C%20account%20processing%2C%0A%23%20and%20session%20processing.%20If%20this%20is%20enabled%2C%20PAM%20authentication%20will%0A%23%20be%20allowed%20through%20the%20ChallengeResponseAuthentication%20and%0A%23%20PasswordAuthentication.%20%20Depending%20on%20your%20PAM%20configuration%2C%0A%23%20PAM%20authentication%20via%20ChallengeResponseAuthentication%20may%20bypass%0A%23%20the%20setting%20of%20%22PermitRootLogin%20without-password%22.%0A%23%20If%20you%20just%20want%20the%20PAM%20account%20and%20session%20checks%20to%20run%20without%0A%23%20PAM%20authentication%2C%20then%20enable%20this%20but%20set%20PasswordAuthentication%0A%23%20and%20ChallengeResponseAuthentication%20to%20%27no%27.%0A%23%20WARNING%3A%20%27UsePAM%20no%27%20is%20not%20supported%20in%20Fedora%20and%20may%20cause%20several%0A%23%20problems.%0AUsePAM%20yes%0A%0A%23AllowAgentForwarding%20yes%0A%23AllowTcpForwarding%20yes%0A%23GatewayPorts%20no%0AX11Forwarding%20yes%0A%23X11DisplayOffset%2010%0A%23X11UseLocalhost%20yes%0A%23PermitTTY%20yes%0A%0A%23%20It%20is%20recommended%20to%20use%20pam_motd%20in%20%2Fetc%2Fpam.d%2Fsshd%20instead%20of%20PrintMotd%2C%0A%23%20as%20it%20is%20more%20configurable%20and%20versatile%20than%20the%20built-in%20version.%0APrintMotd%20no%0A%0APrintLastLog%20yes%0A%23TCPKeepAlive%20yes%0APermitUserEnvironment%20no%0ACompression%20no%0AClientAliveInterval%20600%0AClientAliveCountMax%200%0A%23UseDNS%20no%0A%23PidFile%20%2Fvar%2Frun%2Fsshd.pid%0A%23MaxStartups%2010%3A30%3A100%0A%23PermitTunnel%20no%0A%23ChrootDirectory%20none%0A%23VersionAddendum%20none%0A%0A%23%20no%20default%20banner%20path%0ABanner%20%2Fetc%2Fissue%0A%0A%23%20Accept%20locale-related%20environment%20variables%0AAcceptEnv%20LANG%20LC_CTYPE%20LC_NUMERIC%20LC_TIME%20LC_COLLATE%20LC_MONETARY%20LC_MESSAGES%0AAcceptEnv%20LC_PAPER%20LC_NAME%20LC_ADDRESS%20LC_TELEPHONE%20LC_MEASUREMENT%0AAcceptEnv%20LC_IDENTIFICATION%20LC_ALL%20LANGUAGE%0AAcceptEnv%20XMODIFIERS%0A%0A%23%20override%20default%20of%20no%20subsystems%0ASubsystem%09sftp%09%2Fusr%2Flibexec%2Fopenssh%2Fsftp-server%0A%0A%23%20Example%20of%20overriding%20settings%20on%20a%20per-user%20basis%0A%23Match%20User%20anoncvs%0A%23%09X11Forwarding%20no%0A%23%09AllowTcpForwarding%20no%0A%23%09PermitTTY%20no%0A%23%09ForceCommand%20cvs%20server%0A%0AUsePrivilegeSeparation%20sandbox
        mode: 0600
        path: /etc/ssh/sshd_config
        overwrite: true

Complexity:low
Disruption:low
Strategy:restrict
- name: Disable Host-Based Authentication
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter HostbasedAuthentication is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
      line: HostbasedAuthentication no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-8.3.1
  - disable_host_auth
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "HostbasedAuthentication no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "HostbasedAuthentication no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable SSH Access via Empty Passwords   [ref]

Disallow SSH login with empty passwords. The default SSH configuration disables logins with empty passwords. The appropriate configuration is used if no value is set for PermitEmptyPasswords.
To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.
Rationale:
Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords
Identifiers and References

References:  NT007(R17), 11, 12, 13, 14, 15, 16, 18, 3, 5, 9, 5.5.6, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, 3.1.1, 3.1.5, CCI-000366, CCI-000766, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, FIA_UAU.1, Req-2.2.4, 2.2.6, SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable SSH Access via Empty Passwords
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter PermitEmptyPasswords is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
      line: PermitEmptyPasswords no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_empty_passwords

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "PermitEmptyPasswords no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "PermitEmptyPasswords no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable GSSAPI Authentication   [ref]

Unless needed, SSH should not permit extraneous or unnecessary authentication mechanisms like GSSAPI.
The default SSH configuration disallows authentications based on GSSAPI. The appropriate configuration is used if no value is set for GSSAPIAuthentication.
To explicitly disable GSSAPI authentication, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
GSSAPIAuthentication no
Rationale:
GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_gssapi_auth
Identifiers and References

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000318, CCI-000368, CCI-001812, CCI-001813, CCI-001814, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, 0418, 1055, 1402, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-7(a), CM-7(b), CM-6(a), AC-17(a), PR.IP-1, FTP_ITC_EXT.1, FCS_SSH_EXT.1.2, SRG-OS-000364-GPOS-00151, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable GSSAPI Authentication
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "GSSAPIAuthentication"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter GSSAPIAuthentication is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "GSSAPIAuthentication"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "GSSAPIAuthentication"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "GSSAPIAuthentication"| regex_escape }}\s+
      line: GSSAPIAuthentication no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_gssapi_auth

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*GSSAPIAuthentication\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*GSSAPIAuthentication\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*GSSAPIAuthentication\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "GSSAPIAuthentication no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "GSSAPIAuthentication no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable Kerberos Authentication   [ref]

Unless needed, SSH should not permit extraneous or unnecessary authentication mechanisms like Kerberos.
The default SSH configuration disallows authentication validation through Kerberos. The appropriate configuration is used if no value is set for KerberosAuthentication.
To explicitly disable Kerberos authentication, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
KerberosAuthentication no
Rationale:
Kerberos authentication for SSH is often implemented using GSSAPI. If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Configuring these settings for the SSH daemon provides additional assurance that remote logon via SSH will not use unused methods of authentication, even in the event of misconfiguration elsewhere.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_kerb_auth
Identifiers and References

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000318, CCI-000368, CCI-001812, CCI-001813, CCI-001814, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, FTP_ITC_EXT.1, FCS_SSH_EXT.1.2, SRG-OS-000364-GPOS-00151, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable Kerberos Authentication
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "KerberosAuthentication"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter KerberosAuthentication is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "KerberosAuthentication"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "KerberosAuthentication"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "KerberosAuthentication"| regex_escape }}\s+
      line: KerberosAuthentication no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_kerb_auth

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*KerberosAuthentication\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*KerberosAuthentication\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*KerberosAuthentication\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "KerberosAuthentication no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "KerberosAuthentication no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable SSH Support for .rhosts Files   [ref]

SSH can emulate the behavior of the obsolete rsh command in allowing users to enable insecure access to their accounts via .rhosts files.
The default SSH configuration disables support for .rhosts. The appropriate configuration is used if no value is set for IgnoreRhosts.
To explicitly disable support for .rhosts files, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
IgnoreRhosts yes
Rationale:
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_rhosts
Identifiers and References

References:  11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_UAU.1, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable SSH Support for .rhosts Files
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter IgnoreRhosts is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
      line: IgnoreRhosts yes
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_rhosts

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "IgnoreRhosts yes" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "IgnoreRhosts yes" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable SSH TCP Forwarding   [ref]

The AllowTcpForwarding parameter specifies whether TCP forwarding is permitted. To disable TCP forwarding, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
AllowTcpForwarding no
Rationale:
Leaving port forwarding enabled can expose the organization to security risks and back-doors.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_tcp_forwarding
Identifiers and References

References:  2.2.6


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable SSH TCP Forwarding
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter AllowTcpForwarding is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      create: true
      regexp: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
      line: AllowTcpForwarding no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_tcp_forwarding

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "AllowTcpForwarding no" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    printf '%s\n' "AllowTcpForwarding no" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Disable X11 Forwarding   [ref]

The X11Forwarding parameter provides the ability to tunnel X11 traffic through the connection to enable remote graphic connections. SSH has the capability to encrypt remote X11 connections when SSH's X11Forwarding option is enabled.
The default SSH configuration disables X11Forwarding. The appropriate configuration is used if no value is set for X11Forwarding.
To explicitly disable X11 Forwarding, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
X11Forwarding no
Rationale:
Disable X11 forwarding unless there is an operational requirement to use X11 applications directly. There is a small risk that the remote X11 servers of users who are logged in via SSH with X11 forwarding could be compromised by other users on the X11 server. Note that even if X11 forwarding is disabled, users can always install their own forwarders.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_disable_x11_forwarding
Identifiers and References

References:  CCI-000366, CM-6(b), 2.2.4, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Disable X11 Forwarding
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter X11Forwarding is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
      line: X11Forwarding no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(b)
  - PCI-DSSv4-2.2.4
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_x11_forwarding

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "X11Forwarding no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "X11Forwarding no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Do Not Allow SSH Environment Options   [ref]

Ensure that users are not able to override environment variables of the SSH daemon.
The default SSH configuration disables environment processing. The appropriate configuration is used if no value is set for PermitUserEnvironment.
To explicitly disable Environment options, add or correct the following /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
PermitUserEnvironment no
Rationale:
SSH environment options potentially allow users to bypass access restriction in some configurations.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_do_not_permit_user_env
Identifiers and References

References:  11, 3, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, Req-2.2.4, 2.2.6, SRG-OS-000480-GPOS-00229


Complexity:low
Disruption:low
Strategy:restrict
- name: Do Not Allow SSH Environment Options
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter PermitUserEnvironment is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
      line: PermitUserEnvironment no
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_do_not_permit_user_env

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "PermitUserEnvironment no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "PermitUserEnvironment no" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable PAM   [ref]

UsePAM Enables the Pluggable Authentication Module interface. If set to “yes” this will enable PAM authentication using ChallengeResponseAuthentication and PasswordAuthentication in addition to PAM account and session module processing for all authentication types. To enable PAM authentication, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
UsePAM yes
Rationale:
When UsePAM is set to yes, PAM runs through account and session types properly. This is important if you want to restrict access to services based off of IP, time or other factors of the account. Additionally, you can make sure users inherit certain environment variables on login or disallow access to the server.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_enable_pam
Identifiers and References

References:  CCI-000877, 2.2.4, SRG-OS-000125-GPOS-00065


Complexity:low
Disruption:low
Strategy:restrict
- name: Enable PAM
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter UsePAM is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      create: true
      regexp: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+
      line: UsePAM yes
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.4
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_enable_pam

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "UsePAM yes" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    printf '%s\n' "UsePAM yes" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Enable Use of Strict Mode Checking   [ref]

SSHs StrictModes option checks file and ownership permissions in the user's home directory .ssh folder before accepting login. If world- writable permissions are found, logon is rejected.
The default SSH configuration has StrictModes enabled. The appropriate configuration is used if no value is set for StrictModes.
To explicitly enable StrictModes in SSH, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
StrictModes yes
Rationale:
If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_enable_strictmodes
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6, AC-17(a), CM-6(a), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Enable Use of Strict Mode Checking
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "StrictModes"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter StrictModes is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "StrictModes"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "StrictModes"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "StrictModes"| regex_escape }}\s+
      line: StrictModes yes
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6
  - NIST-800-53-CM-6(a)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_enable_strictmodes

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*StrictModes\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*StrictModes\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*StrictModes\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "StrictModes yes" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "StrictModes yes" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Force frequent session key renegotiation   [ref]

The RekeyLimit parameter specifies how often the session key of the is renegotiated, both in terms of amount of data that may be transmitted and the time elapsed.
To decrease the default limits, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
RekeyLimit 1G 1h
Rationale:
By decreasing the limit based on the amount of data and enabling time-based limit, effects of potential attacks against encryption keys are limited.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_rekey_limit
Identifiers and References

References:  CCI-000068, FCS_SSH_EXT.1.8, SRG-OS-000480-GPOS-00227, SRG-OS-000033-GPOS-00014


Complexity:low
Disruption:low
Strategy:configure
- name: XCCDF Value var_rekey_limit_size # promote to variable
  set_fact:
    var_rekey_limit_size: !!str 1G
  tags:
    - always
- name: XCCDF Value var_rekey_limit_time # promote to variable
  set_fact:
    var_rekey_limit_time: !!str 1h
  tags:
    - always

- name: Force frequent session key renegotiation
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "RekeyLimit"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter RekeyLimit is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "RekeyLimit"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "RekeyLimit"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      create: true
      regexp: (?i)^\s*{{ "RekeyLimit"| regex_escape }}\s+
      line: RekeyLimit {{ var_rekey_limit_size }} {{ var_rekey_limit_time }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sshd_rekey_limit

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_rekey_limit_size='1G'
var_rekey_limit_time='1h'



mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

LC_ALL=C sed -i "/^\s*RekeyLimit\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*RekeyLimit\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*RekeyLimit\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "RekeyLimit $var_rekey_limit_size $var_rekey_limit_time" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    printf '%s\n' "RekeyLimit $var_rekey_limit_size $var_rekey_limit_time" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH Daemon LogLevel to VERBOSE   [ref]

The VERBOSE parameter configures the SSH daemon to record login and logout activity. To specify the log level in SSH, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:
LogLevel VERBOSE
Rationale:
SSH provides several logging levels with varying amounts of verbosity. DEBUG is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information. INFO or VERBOSE level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_loglevel_verbose
Identifiers and References

References:  CCI-000067, CIP-007-3 R7.1, AC-17(a), AC-17(1), CM-6(a), Req-2.2.4, 2.2.6, SRG-OS-000032-GPOS-00013


Complexity:low
Disruption:low
Strategy:restrict
- name: Set SSH Daemon LogLevel to VERBOSE
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter LogLevel is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      create: true
      regexp: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+
      line: LogLevel VERBOSE
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-17(1)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_loglevel_verbose

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "LogLevel VERBOSE" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    printf '%s\n' "LogLevel VERBOSE" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH authentication attempt limit   [ref]

The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. Once the number of failures reaches half this value, additional failures are logged. to set MaxAUthTries edit /etc/ssh/sshd_config as follows:
MaxAuthTries 4
Rationale:
Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_max_auth_tries
Identifiers and References

References:  0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 2.2.6


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value sshd_max_auth_tries_value # promote to variable
  set_fact:
    sshd_max_auth_tries_value: !!str 4
  tags:
    - always

- name: Set SSH authentication attempt limit
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*MaxAuthTries\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*MaxAuthTries\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxAuthTries\s+
      line: MaxAuthTries {{ sshd_max_auth_tries_value }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_max_auth_tries

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

sshd_max_auth_tries_value='4'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*MaxAuthTries\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "MaxAuthTries $sshd_max_auth_tries_value" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "MaxAuthTries $sshd_max_auth_tries_value" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Set SSH MaxSessions limit   [ref]

The MaxSessions parameter specifies the maximum number of open sessions permitted from a given connection. To set MaxSessions edit /etc/ssh/sshd_config as follows:
MaxSessions 10
Rationale:
To protect a system from denial of service due to a large number of concurrent sessions, use the rate limiting function of MaxSessions to protect availability of sshd logins and prevent overwhelming the daemon.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_max_sessions
Identifiers and References

References:  2.2.6


Complexity:low
Disruption:low
Strategy:configure
- name: XCCDF Value var_sshd_max_sessions # promote to variable
  set_fact:
    var_sshd_max_sessions: !!str 10
  tags:
    - always

- name: Set SSH MaxSessions limit
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*MaxSessions\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*MaxSessions\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxSessions\s+
      line: MaxSessions {{ var_sshd_max_sessions }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sshd_set_max_sessions

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_sshd_max_sessions='10'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*MaxSessions\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "MaxSessions $var_sshd_max_sessions" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "MaxSessions $var_sshd_max_sessions" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Ensure SSH MaxStartups is configured   [ref]

The MaxStartups parameter specifies the maximum number of concurrent unauthenticated connections to the SSH daemon. Additional connections will be dropped until authentication succeeds or the LoginGraceTime expires for a connection. To confgure MaxStartups, you should add or correct the following line in the /etc/ssh/sshd_config file:
MaxStartups 10:30:60
CIS recommends a MaxStartups value of '10:30:60', or more restrictive where dictated by site policy.
Rationale:
To protect a system from denial of service due to a large number of pending authentication connection attempts, use the rate limiting function of MaxStartups to protect availability of sshd logins and prevent overwhelming the daemon.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_maxstartups
Identifiers and References

References:  2.2.6


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_sshd_set_maxstartups # promote to variable
  set_fact:
    var_sshd_set_maxstartups: !!str 10:30:60
  tags:
    - always

- name: Ensure SSH MaxStartups is configured
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*MaxStartups\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*MaxStartups\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*MaxStartups\s+
      line: MaxStartups {{ var_sshd_set_maxstartups }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_maxstartups

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_sshd_set_maxstartups='10:30:60'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*MaxStartups\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "MaxStartups $var_sshd_set_maxstartups" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "MaxStartups $var_sshd_set_maxstartups" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   SSH server uses strong entropy to seed   [ref]

To set up SSH server to use entropy from a high-quality source, edit the /etc/sysconfig/sshd file. The SSH_USE_STRONG_RNG configuration value determines how many bytes of entropy to use, so make sure that the file contains line
SSH_USE_STRONG_RNG=32
Warning:  This setting can cause problems on computers without the hardware random generator, because insufficient entropy causes the connection to be blocked until enough entropy is available.
Rationale:
SSH implementation in Fedora uses the openssl library, which doesn't use high-entropy sources by default. Randomness is needed to generate data-encryption keys, and as plaintext padding and initialization vectors in encryption algorithms, and high-quality entropy elliminates the possibility that the output of the random number generator used by SSH would be known to potential attackers.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_sshd_use_strong_rng
Identifiers and References

References:  CCI-000366, FCS_RBG_EXT.1.2, SRG-OS-000480-GPOS-00232, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Setting unquoted shell-style assignment of 'SSH_USE_STRONG_RNG' to '32' in
    '/etc/sysconfig/sshd'
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/sysconfig/sshd
      create: false
      regexp: ^\s*SSH_USE_STRONG_RNG=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/sysconfig/sshd
    lineinfile:
      path: /etc/sysconfig/sshd
      create: false
      regexp: ^\s*SSH_USE_STRONG_RNG=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/sysconfig/sshd
    lineinfile:
      path: /etc/sysconfig/sshd
      create: true
      regexp: ^\s*SSH_USE_STRONG_RNG=
      line: SSH_USE_STRONG_RNG=32
      state: present
      insertbefore: ^# SSH_USE_STRONG_RNG
      validate: /usr/bin/bash -n %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_use_strong_rng

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

if [ -e "/etc/sysconfig/sshd" ] ; then
    
    LC_ALL=C sed -i "/^\s*SSH_USE_STRONG_RNG\s*=\s*/d" "/etc/sysconfig/sshd"
else
    touch "/etc/sysconfig/sshd"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/sysconfig/sshd"

cp "/etc/sysconfig/sshd" "/etc/sysconfig/sshd.bak"
# Insert before the line matching the regex '^#\s*SSH_USE_STRONG_RNG'.
line_number="$(LC_ALL=C grep -n "^#\s*SSH_USE_STRONG_RNG" "/etc/sysconfig/sshd.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^#\s*SSH_USE_STRONG_RNG', insert at
    # the end of the file.
    printf '%s\n' "SSH_USE_STRONG_RNG=32" >> "/etc/sysconfig/sshd"
else
    head -n "$(( line_number - 1 ))" "/etc/sysconfig/sshd.bak" > "/etc/sysconfig/sshd"
    printf '%s\n' "SSH_USE_STRONG_RNG=32" >> "/etc/sysconfig/sshd"
    tail -n "+$(( line_number ))" "/etc/sysconfig/sshd.bak" >> "/etc/sysconfig/sshd"
fi
# Clean up after ourselves.
rm "/etc/sysconfig/sshd.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Prevent remote hosts from connecting to the proxy display   [ref]

The SSH daemon should prevent remote hosts from connecting to the proxy display.
The default SSH configuration for X11UseLocalhost is yes, which prevents remote hosts from connecting to the proxy display.
To explicitly prevent remote connections to the proxy display, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf: X11UseLocalhost yes
Rationale:
When X11 forwarding is enabled, there may be additional exposure to the server and client displays if the sshd proxy display is configured to listen on the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the DISPLAY environment variable to localhost. This prevents remote hosts from connecting to the proxy display.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_x11_use_localhost
Identifiers and References

References:  CCI-000366, CM-6(b), SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:restrict
- name: Prevent remote hosts from connecting to the proxy display
  block:

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*{{ "X11UseLocalhost"| regex_escape }}\s+
      state: absent

  - name: Check if /etc/ssh/sshd_config.d exists
    stat:
      path: /etc/ssh/sshd_config.d
    register: _etc_ssh_sshd_config_d_exists

  - name: Check if the parameter X11UseLocalhost is present in /etc/ssh/sshd_config.d
    find:
      paths: /etc/ssh/sshd_config.d
      recurse: 'yes'
      follow: 'no'
      contains: (?i)^\s*{{ "X11UseLocalhost"| regex_escape }}\s+
    register: _etc_ssh_sshd_config_d_has_parameter
    when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

  - name: Remove parameter from files in /etc/ssh/sshd_config.d
    lineinfile:
      path: '{{ item.path }}'
      create: false
      regexp: (?i)^\s*{{ "X11UseLocalhost"| regex_escape }}\s+
      state: absent
    with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
    when: _etc_ssh_sshd_config_d_has_parameter.matched

  - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    lineinfile:
      path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      create: true
      regexp: (?i)^\s*{{ "X11UseLocalhost"| regex_escape }}\s+
      line: X11UseLocalhost yes
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(b)
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_x11_use_localhost

Complexity:low
Disruption:low
Strategy:restrict
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

mkdir -p /etc/ssh/sshd_config.d
touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

LC_ALL=C sed -i "/^\s*X11UseLocalhost\s\+/Id" "/etc/ssh/sshd_config"
LC_ALL=C sed -i "/^\s*X11UseLocalhost\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then
    
    LC_ALL=C sed -i "/^\s*X11UseLocalhost\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "X11UseLocalhost yes" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    printf '%s\n' "X11UseLocalhost yes" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Group Who Owns SSH Server config file   [ref]

To properly set the group owner of /etc/ssh/sshd_config, run the command:
$ sudo chgrp root /etc/ssh/sshd_config
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_groupowner_sshd_config
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/ssh/sshd_config
  stat:
    path: /etc/ssh/sshd_config
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/ssh/sshd_config
  file:
    path: /etc/ssh/sshd_config
    group: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chgrp 0 /etc/ssh/sshd_config

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Owner on SSH Server config file   [ref]

To properly set the owner of /etc/ssh/sshd_config, run the command:
$ sudo chown root /etc/ssh/sshd_config 
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_sshd_config
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/ssh/sshd_config
  stat:
    path: /etc/ssh/sshd_config
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/ssh/sshd_config
  file:
    path: /etc/ssh/sshd_config
    owner: '0'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chown 0 /etc/ssh/sshd_config

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on SSH Server config file   [ref]

To properly set the permissions of /etc/ssh/sshd_config, run the command:
$ sudo chmod 0600 /etc/ssh/sshd_config
Rationale:
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_sshd_config
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/ssh/sshd_config
  stat:
    path: /etc/ssh/sshd_config
  register: file_exists
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/ssh/sshd_config
  file:
    path: /etc/ssh/sshd_config
    mode: u-xs,g-xwrs,o-xwrt
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_config
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

chmod u-xs,g-xwrs,o-xwrt /etc/ssh/sshd_config

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on SSH Server Private *_key Key Files   [ref]

SSH server private keys - files that match the /etc/ssh/*_key glob, have to have restricted permissions. If those files are owned by the root user and the root group, they have to have the 0600 permission or stricter. If they are owned by the root user, but by a dedicated group ssh_keys, they can have the 0640 permission or stricter.
Rationale:
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_sshd_private_key
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.13, 3.13.10, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-2.2.4, 2.2.6, SRG-OS-000480-GPOS-00227


include ssh_private_key_perms

class ssh_private_key_perms {
  exec { 'sshd_priv_key':
    command => "chmod 0640 /etc/ssh/*_key",
    path    => '/bin:/usr/bin'
  }
}

Complexity:low
Disruption:low
Strategy:configure
- name: Find root:root-owned keys
  ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
    -type f -group root -perm /u+xs,g+xwrs,o+xwrt
  register: root_owned_keys
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for root:root-owned keys
  ansible.builtin.file:
    path: '{{ item }}'
    mode: u-xs,g-xwrs,o-xwrt
    state: file
  with_items:
  - '{{ root_owned_keys.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Find root:ssh_keys-owned keys
  ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
    -type f -group ssh_keys -perm /u+xs,g+xws,o+xwrt
  register: dedicated_group_owned_keys
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for root:ssh_keys-owned keys
  ansible.builtin.file:
    path: '{{ item }}'
    mode: u-xs,g-xws,o-xwrt
    state: file
  with_items:
  - '{{ dedicated_group_owned_keys.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

for keyfile in /etc/ssh/*_key; do
    test -f "$keyfile" || continue
    if test root:root = "$(stat -c "%U:%G" "$keyfile")"; then
    
	chmod u-xs,g-xwrs,o-xwrt "$keyfile"
    
    elif test root:ssh_keys = "$(stat -c "%U:%G" "$keyfile")"; then
	chmod u-xs,g-xws,o-xwrt "$keyfile"
    else
        echo "Key-like file '$keyfile' is owned by an unexpected user:group combination"
    fi
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Rule   Verify Permissions on SSH Server Public *.pub Key Files   [ref]

To properly set the permissions of /etc/ssh/*.pub, run the command:
$ sudo chmod 0644 /etc/ssh/*.pub
Rationale:
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_sshd_pub_key
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.13, 3.13.10, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-2.2.4, 2.2.6, SRG-OS-000480-GPOS-00227


include ssh_public_key_perms

class ssh_public_key_perms {
  exec { 'sshd_pub_key':
    command => "chmod 0644 /etc/ssh/*.pub",
    path    => '/bin:/usr/bin'
  }
}

Complexity:low
Disruption:low
Strategy:configure
- name: Find /etc/ssh/ file(s)
  command: find -H /etc/ssh/ -maxdepth 1 -perm /u+xs,g+xws,o+xwt  -type f -regex "^.*\.pub$"
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_pub_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for /etc/ssh/ file(s)
  file:
    path: '{{ item }}'
    mode: u-xs,g-xws,o-xwt
    state: file
  with_items:
  - '{{ files_found.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_pub_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

find -H /etc/ssh/ -maxdepth 1 -perm /u+xs,g+xws,o+xwt  -type f -regex '^.*\.pub$' -exec chmod u-xs,g-xws,o-xwt {} \;

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
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