Guide to the Secure Configuration of Red Hat Virtualization 4

with profile VPP - Protection Profile for Virtualization v. 1.0 for Red Hat Virtualization Host (RHVH)
This compliance profile reflects the core set of security related configuration settings for deployment of Red Hat Virtualization Host (RHVH) 4.x into U.S. Defense, Intelligence, and Civilian agencies. Development partners and sponsors include the U.S. National Institute of Standards and Technology (NIST), U.S. Department of Defense, the National Security Agency, and Red Hat. This baseline implements configuration requirements from the following sources: - Committee on National Security Systems Instruction No. 1253 (CNSSI 1253) - NIST 800-53 control selections for MODERATE impact systems (NIST 800-53) - U.S. Government Configuration Baseline (USGCB) - NIAP Protection Profile for Virtualization v1.0 (VPP v1.0) For any differing configuration requirements, e.g. password lengths, the stricter security setting was chosen. Security Requirement Traceability Guides (RTMs) and sample System Security Configuration Guides are provided via the scap-security-guide-docs package. This profile reflects U.S. Government consensus content and is developed through the ComplianceAsCode project, championed by the National Security Agency. Except for differences in formatting to accommodate publishing processes, this profile mirrors ComplianceAsCode content as minor divergences, such as bugfixes, work through the consensus and release processes.
This guide presents a catalog of security-relevant configuration settings for Red Hat Virtualization 4. 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 TitleVPP - Protection Profile for Virtualization v. 1.0 for Red Hat Virtualization Host (RHVH)
Profile IDxccdf_org.ssgproject.content_profile_rhvh-vpp

CPE Platforms

  • cpe:/o:redhat:enterprise_linux:8::hypervisor
  • cpe:/a:redhat:enterprise_virtualization_manager:4

Revision History

Current version: 0.1.55

  • draft (as of 2021-03-19)

Table of Contents

  1. System Settings
    1. Installing and Maintaining Software
    2. Account and Access Control
    3. System Accounting with auditd
    4. File Permissions and Masks
    5. GRUB2 bootloader configuration
    6. Network Configuration and Firewalls
    7. SELinux
  2. Services
    1. SSH Server
    2. System Security Services Daemon

Checklist

Group   Guide to the Secure Configuration of Red Hat Virtualization 4   Group contains 49 groups and 143 rules
Group   System Settings   Group contains 44 groups and 126 rules
[ref]   Contains rules that check correct system settings.
Group   Installing and Maintaining Software   Group contains 7 groups and 17 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 5 groups and 12 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   Software Integrity Checking   Group contains 1 group and 3 rules
[ref]   Both the AIDE (Advanced Intrusion Detection Environment) software and the RPM package management system provide mechanisms for verifying the integrity of installed software. AIDE uses snapshots of file metadata (such as hashes) and compares these to current system files in order to detect changes.

The RPM package management system can conduct integrity checks by comparing information in its metadata database with files installed on the system.
Group   Verify Integrity with RPM   Group contains 3 rules
[ref]   The RPM package management system includes the ability to verify the integrity of installed packages by comparing the installed files with information about the files taken from the package metadata stored in the RPM database. Although an attacker could corrupt the RPM database (analogous to attacking the AIDE database as described above), this check can still reveal modification of important files. To list which files on the system differ from what is expected by the RPM database:
$ rpm -qVa
See the man page for rpm to see a complete explanation of each column.

Rule   Verify and Correct Ownership with RPM   [ref]

The RPM package management system can check file ownership permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions, which can be found with
rpm -Va | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }'
run the following command to determine which package owns it:
$ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --setugids PACKAGENAME
Warning:  Profiles may require that specific files be owned by root while the default owner defined by the vendor is different. Such files will be reported as a finding and need to be evaluated according to your policy and deployment environment.
Rationale:
Ownership of binaries and configuration files that is incorrect could allow an unauthorized user to gain privileges that they should not have. The ownership set by the vendor should be maintained. Any deviations from this baseline should be investigated.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_rpm_verify_ownership
Identifiers and References

References:  5.10.4.1, 3.3.8, 3.4.1, CCI-001494, CCI-001496, CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3), PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, Req-11.5, SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000278-GPOS-00108, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, 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.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.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9


Complexity:high
Disruption:medium
Strategy:restrict

# Declare array to hold set of RPM packages we need to correct permissions for
declare -A SETPERMS_RPM_DICT

# Create a list of files on the system having permissions different from what
# is expected by the RPM database
readarray -t FILES_WITH_INCORRECT_PERMS < <(rpm -Va --nofiledigest | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }')

for FILE_PATH in "${FILES_WITH_INCORRECT_PERMS[@]}"
do
        RPM_PACKAGE=$(rpm -qf "$FILE_PATH")
	# Use an associative array to store packages as it's keys, not having to care about duplicates.
	SETPERMS_RPM_DICT["$RPM_PACKAGE"]=1
done

# For each of the RPM packages left in the list -- reset its permissions to the
# correct values
for RPM_PACKAGE in "${!SETPERMS_RPM_DICT[@]}"
do
        rpm --setugids "${RPM_PACKAGE}"
done

Complexity:high
Disruption:medium
Strategy:restrict
- name: Read list of files with incorrect ownership
  command: rpm -Va --nodeps --nosignature --nofiledigest --nosize --nomtime --nordev
    --nocaps --nolinkto --nomode
  args:
    warn: false
  register: files_with_incorrect_ownership
  failed_when: files_with_incorrect_ownership.rc > 1
  changed_when: false
  check_mode: false
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_ownership

- name: Create list of packages
  command: rpm -qf "{{ item }}"
  args:
    warn: false
  with_items: '{{ files_with_incorrect_ownership.stdout_lines | map(''regex_findall'',
    ''^[.]+[U|G]+.* (\/.*)'', ''\1'') | map(''join'') | select(''match'', ''(\/.*)'')
    | list | unique }}'
  register: list_of_packages
  changed_when: false
  check_mode: false
  when: (files_with_incorrect_ownership.stdout_lines | length > 0)
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_ownership

- name: Correct file ownership with RPM
  command: rpm --quiet --setugids '{{ item }}'
  args:
    warn: false
  with_items: '{{ list_of_packages.results | map(attribute=''stdout_lines'') | list
    | unique }}'
  when: (files_with_incorrect_ownership.stdout_lines | length > 0)
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_ownership

Rule   Verify and Correct File Permissions with RPM   [ref]

The RPM package management system can check file access permissions of installed software packages, including many that are important to system security. Verify that the file permissions of system files and commands match vendor values. Check the file permissions with the following command:
$ sudo rpm -Va | awk '{ if (substr($0,2,1)=="M") print $NF }'
Output indicates files that do not match vendor defaults. After locating a file with incorrect permissions, run the following command to determine which package owns it:
$ rpm -qf FILENAME

Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --setperms PACKAGENAME
Warning:  Profiles may require that specific files have stricter file permissions than defined by the vendor. Such files will be reported as a finding and need to be evaluated according to your policy and deployment environment.
Rationale:
Permissions on system binaries and configuration files that are too generous could allow an unauthorized user to gain privileges that they should not have. The permissions set by the vendor should be maintained. Any deviations from this baseline should be investigated.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_rpm_verify_permissions
Identifiers and References

References:  5.10.4.1, 3.3.8, 3.4.1, CCI-001493, CCI-001494, CCI-001495, CCI-001496, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3), CM-6(a), PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, Req-11.5, SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099, SRG-OS-000278-GPOS-00108, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, 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.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.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9


Complexity:high
Disruption:medium
Strategy:restrict

# Declare array to hold set of RPM packages we need to correct permissions for
declare -A SETPERMS_RPM_DICT

# Create a list of files on the system having permissions different from what
# is expected by the RPM database
readarray -t FILES_WITH_INCORRECT_PERMS < <(rpm -Va --nofiledigest | awk '{ if (substr($0,2,1)=="M") print $NF }')

for FILE_PATH in "${FILES_WITH_INCORRECT_PERMS[@]}"
do
        # NOTE: some files maybe controlled by more then one package
        readarray -t RPM_PACKAGES < <(rpm -qf "${FILE_PATH}")
        for RPM_PACKAGE in "${RPM_PACKAGES[@]}"
        do
                # Use an associative array to store packages as it's keys, not having to care about duplicates.
                SETPERMS_RPM_DICT["$RPM_PACKAGE"]=1
        done
done

# For each of the RPM packages left in the list -- reset its permissions to the
# correct values
for RPM_PACKAGE in "${!SETPERMS_RPM_DICT[@]}"
do
	rpm --restore "${RPM_PACKAGE}"
done

Complexity:high
Disruption:medium
Strategy:restrict
- name: Read list of files with incorrect permissions
  command: rpm -Va --nodeps --nosignature --nofiledigest --nosize --nomtime --nordev
    --nocaps --nolinkto --nouser --nogroup
  args:
    warn: false
  register: files_with_incorrect_permissions
  failed_when: files_with_incorrect_permissions.rc > 1
  changed_when: false
  check_mode: false
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_permissions

- name: Create list of packages
  command: rpm -qf "{{ item }}"
  args:
    warn: false
  with_items: '{{ files_with_incorrect_permissions.stdout_lines | map(''regex_findall'',
    ''^[.]+[M]+.* (\/.*)'', ''\1'') | map(''join'') | select(''match'', ''(\/.*)'')
    | list | unique }}'
  register: list_of_packages
  changed_when: false
  check_mode: false
  when: (files_with_incorrect_permissions.stdout_lines | length > 0)
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_permissions

- name: Correct file permissions with RPM
  command: rpm --setperms '{{ item }}'
  args:
    warn: false
  with_items: '{{ list_of_packages.results | map(attribute=''stdout_lines'') | list
    | unique }}'
  when: (files_with_incorrect_permissions.stdout_lines | length > 0)
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_permissions

Rule   Verify File Hashes with RPM   [ref]

Without cryptographic integrity protections, system executables and files can be altered by unauthorized users without detection. The RPM package management system can check the hashes of installed software packages, including many that are important to system security. To verify that the cryptographic hash of system files and commands matches vendor values, run the following command to list which files on the system have hashes that differ from what is expected by the RPM database:
$ rpm -Va --noconfig | grep '^..5'
A "c" in the second column indicates that a file is a configuration file, which may appropriately be expected to change. If the file was not expected to change, investigate the cause of the change using audit logs or other means. The package can then be reinstalled to restore the file. Run the following command to determine which package owns the file:
$ rpm -qf FILENAME
The package can be reinstalled from a yum repository using the command:
$ sudo yum reinstall PACKAGENAME
Alternatively, the package can be reinstalled from trusted media using the command:
$ sudo rpm -Uvh PACKAGENAME
Rationale:
The hashes of important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_rpm_verify_hashes
Identifiers and References

References:  1.2.6, 5.10.4.1, 3.3.8, 3.4.1, CCI-000366, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3), PR.DS-6, PR.DS-8, PR.IP-1, Req-11.5, SRG-OS-000480-GPOS-00227, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, 11, 2, 3, 9



# Find which files have incorrect hash (not in /etc, because of the system related config files) and then get files names
files_with_incorrect_hash="$(rpm -Va --noconfig | grep -E '^..5' | awk '{print $NF}' )"

# From files names get package names and change newline to space, because rpm writes each package to new line
packages_to_reinstall="$(rpm -qf $files_with_incorrect_hash | tr '\n' ' ')"

yum reinstall -y $packages_to_reinstall

Complexity:high
Disruption:medium
Strategy:restrict
- name: 'Set fact: Package manager reinstall command (dnf)'
  set_fact:
    package_manager_reinstall_cmd: dnf reinstall -y
  when: ansible_distribution == "Fedora"
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_hashes

- name: 'Set fact: Package manager reinstall command (yum)'
  set_fact:
    package_manager_reinstall_cmd: yum reinstall -y
  when: (ansible_distribution == "RedHat" or ansible_distribution == "OracleLinux")
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_hashes

- name: Read files with incorrect hash
  command: rpm -Va --nodeps --nosize --nomtime --nordev --nocaps --nolinkto --nouser
    --nogroup --nomode --noghost --noconfig
  args:
    warn: false
  register: files_with_incorrect_hash
  changed_when: false
  failed_when: files_with_incorrect_hash.rc > 1
  check_mode: false
  when: (package_manager_reinstall_cmd is defined)
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_hashes

- name: Create list of packages
  command: rpm -qf "{{ item }}"
  args:
    warn: false
  with_items: '{{ files_with_incorrect_hash.stdout_lines | map(''regex_findall'',
    ''^[.]+[5]+.* (\/.*)'', ''\1'') | map(''join'') | select(''match'', ''(\/.*)'')
    | list | unique }}'
  register: list_of_packages
  changed_when: false
  check_mode: false
  when:
    - files_with_incorrect_hash.stdout_lines is defined
    - (files_with_incorrect_hash.stdout_lines | length > 0)
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_hashes

- name: Reinstall packages of files with incorrect hash
  command: '{{ package_manager_reinstall_cmd }} ''{{ item }}'''
  args:
    warn: false
  with_items: '{{ list_of_packages.results | map(attribute=''stdout_lines'') | list
    | unique }}'
  when:
    - files_with_incorrect_hash.stdout_lines is defined
    - (package_manager_reinstall_cmd is defined and (files_with_incorrect_hash.stdout_lines
      | length > 0))
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.3.8
    - NIST-800-171-3.4.1
    - NIST-800-53-AU-9(3)
    - NIST-800-53-CM-6(c)
    - NIST-800-53-CM-6(d)
    - NIST-800-53-SI-7
    - NIST-800-53-SI-7(1)
    - NIST-800-53-SI-7(6)
    - PCI-DSS-Req-11.5
    - high_complexity
    - high_severity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
    - rpm_verify_hashes
Group   Federal Information Processing Standard (FIPS)   Group contains 1 rule
[ref]   The Federal Information Processing Standard (FIPS) is a computer security standard which is developed by the U.S. Government and industry working groups to validate the quality of cryptographic modules. The FIPS standard provides four security levels to ensure adequate coverage of different industries, implementation of cryptographic modules, and organizational sizes and requirements.

FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets industry and government requirements. For government systems, this allows Security Levels 1, 2, 3, or 4 for use on Red Hat Virtualization 4.

See http://csrc.nist.gov/publications/PubsFIPS.html for more information.

Rule   Enable FIPS Mode   [ref]

To enable FIPS mode, run the following command:
fips-mode-setup --enable

The fips-mode-setup command will configure the system in FIPS mode by automatically configuring the following:
  • Setting the kernel FIPS mode flag (/proc/sys/crypto/fips_enabled) to 1
  • Creating /etc/system-fips
  • Setting the system crypto policy in /etc/crypto-policies/config to FIPS
  • Loading the Dracut fips module
Furthermore, the system running in FIPS mode should be FIPS certified by NIST.
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:
Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_enable_fips_mode
Identifiers and References

References:  CCI-000068, CCI-000803, CCI-002450, SC-12(2), SC-12(3), IA-7, SC-13, CM-6(a), SC-12, SRG-OS-000120-VMM-000600, SRG-OS-000478-VMM-001980, SRG-OS-000396-VMM-001590, 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-000478-GPOS-00223, SRG-OS-000396-GPOS-00176, 1446


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

fips-mode-setup --enable

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   System Cryptographic Policies   Group contains 6 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 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:  AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SRG-OS-000250-GPOS-00093



SSH_CONF="/etc/sysconfig/sshd"

sed -i "/^\s*CRYPTO_POLICY.*$/d" $SSH_CONF

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*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
    - configure_ssh_crypto_policy
    - disable_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - reboot_required

Rule   Configure System Cryptography Policy   [ref]

To configure the system cryptography policy to use ciphers only from the FIPS:OSPP policy, run the following command:
$ sudo update-crypto-policies --set FIPS:OSPP
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:  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, 1446



# include remediation functions library

var_system_crypto_policy="FIPS:OSPP"



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

Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_system_crypto_policy # promote to variable
  set_fact:
    var_system_crypto_policy: !!str FIPS:OSPP
  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

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: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_bind_crypto_policy
Identifiers and References

References:  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 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: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_libreswan_crypto_policy
Identifiers and References

References:  CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), SRG-OS-000033-GPOS-00014, FCS_IPSEC_EXT.1.4, FCS_IPSEC_EXT.1.6



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
        echo 'include /etc/crypto-policies/back-ends/libreswan.config' >> "$CONFIG_FILE"
    fi
    return 0
}

remediate_libreswan_crypto_policy

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
    - configure_libreswan_crypto_policy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

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: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_kerberos_crypto_policy
Identifiers and References

References:  SC-13, SC-12(2), SC-12(3), SRG-OS-000120-GPOS-00061, 0418, 1055, 1402


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

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
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required

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:  AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), SRG-OS-000250-GPOS-00093



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*/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

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
  ignore_errors: true
  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
    - 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
    - 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
    - configure_openssl_crypto_policy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
    - unknown_strategy
Group   Operating System Vendor Support and Certification   Group contains 2 rules
[ref]   The assurance of a vendor to provide operating system support and maintenance for their product is an important criterion to ensure product stability and security over the life of the product. A certified product that follows the necessary standards and government certification requirements guarantees that known software vulnerabilities will be remediated, and proper guidance for protecting and securing the operating system will be given.

Rule   The Installed Operating System Is FIPS 140-2 Certified   [ref]

To enable processing of sensitive information the operating system must provide certified cryptographic modules compliant with FIPS 140-2 standard.
Warning:  There is no remediation besides switching to a different operating system.
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:
The Federal Information Processing Standard (FIPS) Publication 140-2, (FIPS PUB 140-2) is a computer security standard. The standard specifies security requirements for cryptographic modules used to protect sensitive unclassified information. Refer to the full FIPS 140-2 standard at http://csrc.nist.gov/publications/fips/fips140-2/fips1402.pdf for further details on the requirements. FIPS 140-2 validation is required by U.S. law when information systems use cryptography to protect sensitive government information. In order to achieve FIPS 140-2 certification, cryptographic modules are subject to extensive testing by independent laboratories, accredited by National Institute of Standards and Technology (NIST).
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_installed_OS_is_FIPS_certified
Identifiers and References

References:  CCI-000803, CCI-002450, SC-12(2), SC-12(3), IA-7, SC-13, CM-6(a), SC-12, SRG-OS-000120-VMM-000600, SRG-OS-000478-VMM-001980, SRG-OS-000396-VMM-001590

Rule   The Installed Operating System Is Vendor Supported   [ref]

The installed operating system must be maintained by a vendor. Red Hat Enterprise Linux is supported by Red Hat, Inc. As the Red Hat Enterprise Linux vendor, Red Hat, Inc. is responsible for providing security patches.
Warning:  There is no remediation besides switching to a different operating system.
Rationale:
An operating system is considered "supported" if the vendor continues to provide security patches for the product. With an unsupported release, it will not be possible to resolve any security issue discovered in the system software.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_installed_OS_is_vendor_supported
Identifiers and References

References:  CCI-000366, CM-6(a), MA-6, SA-13(a), ID.RA-1, PR.IP-12, SRG-OS-000480-GPOS-00227, 4.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9, APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02, A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3, 18, 20, 4

Group   Updating Software   Group contains 5 rules
[ref]   The yum 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.

Red Hat Virtualization 4 systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using yum or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.

Rule   Ensure gpgcheck Enabled In Main yum Configuration   [ref]

The gpgcheck option controls whether RPM packages' signatures are always checked prior to installation. To configure yum to check package signatures before installing them, ensure the following line appears in /etc/yum.conf in the [main] section:
gpgcheck=1
Rationale:
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA).
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated
Identifiers and References

References:  5.10.4.1, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, 11, 2, 3, 9, BP28(R15)


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

# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append "/etc/yum.conf" '^gpgcheck' '1' ''

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

Complexity:low
Disruption:medium
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Check existence of yum on Fedora
  stat:
    path: /etc/yum.conf
  register: yum_config_file
  check_mode: false
  when:
    - ansible_distribution == "Fedora"
    - '"yum" in ansible_facts.packages'
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check is globally activated (yum)
  ini_file:
    dest: /etc/yum.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when:
    - (ansible_distribution == "RedHat" or ansible_distribution == "CentOS" or ansible_distribution
      == "Scientific" or yum_config_file.stat.exists)
    - '"yum" in ansible_facts.packages'
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check is globally activated (dnf)
  ini_file:
    dest: /etc/dnf/dnf.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when:
    - ansible_distribution == "Fedora"
    - '"yum" in ansible_facts.packages'
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_gpgcheck_globally_activated
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

Rule   Ensure yum Removes Previous Package Versions   [ref]

yum should be configured to remove previous software components after new versions have been installed. To configure yum to remove the previous software components after updating, set the clean_requirements_on_remove to 1 in /etc/yum.conf.
Rationale:
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by some adversaries.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_clean_components_post_updating
Identifiers and References

References:  3.4.8, CCI-002617, SI-2(6), CM-11(a), CM-11(b), CM-6(a), ID.RA-1, PR.IP-12, SRG-OS-000437-GPOS-00194, SRG-OS-000437-VMM-001760, 4.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9, APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02, A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3, 18, 20, 4


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

if grep --silent ^clean_requirements_on_remove /etc/yum.conf ; then
        sed -i "s/^clean_requirements_on_remove.*/clean_requirements_on_remove=1/g" /etc/yum.conf
else
        echo -e "\n# Set clean_requirements_on_remove to 1 per security requirements" >> /etc/yum.conf
        echo "clean_requirements_on_remove=1" >> /etc/yum.conf
fi

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-2(6)
    - clean_components_post_updating
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - restrict_strategy

- name: Ensure YUM Removes Previous Package Versions
  lineinfile:
    dest: /etc/yum.conf
    regexp: ^#?clean_requirements_on_remove
    line: clean_requirements_on_remove=1
    insertafter: \[main\]
    create: true
  when: '"yum" in ansible_facts.packages'
  tags:
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SI-2(6)
    - clean_components_post_updating
    - low_complexity
    - low_disruption
    - low_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure gpgcheck Enabled for Local Packages   [ref]

yum should be configured to verify the signature(s) of local packages prior to installation. To configure yum to verify signatures of local packages, set the localpkg_gpgcheck to 1 in /etc/yum.conf.
Rationale:
Changes to any software components can have significant effects to the overall security of the operating system. This requirement ensures the software has not been tampered and has been provided by a trusted vendor.

Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_local_packages
Identifiers and References

References:  3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), CM-11(a), CM-11(b), CM-6(a), CM-5(3), SA-12, SA-12(10), PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650, SR 7.6, 4.3.4.3.2, 4.3.4.3.3, BAI10.01, BAI10.02, BAI10.03, BAI10.05, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, 11, 3, 9, BP28(R15)


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

# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/yum.conf' '^localpkg_gpgcheck' '1' ''

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

Complexity:low
Disruption:medium
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Check existence of yum on Fedora
  stat:
    path: /etc/yum.conf
  register: yum_config_file
  check_mode: false
  when:
    - ansible_distribution == "Fedora"
    - '"yum" in ansible_facts.packages'
  tags:
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check Enabled for Local Packages (Yum)
  ini_file:
    dest: /etc/yum.conf
    section: main
    option: localpkg_gpgcheck
    value: 1
    create: true
  when:
    - (ansible_distribution == "RedHat" or ansible_distribution == "CentOS" or ansible_distribution
      == "Scientific" or yum_config_file.stat.exists)
    - '"yum" in ansible_facts.packages'
  tags:
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

- name: Ensure GPG check Enabled for Local Packages (DNF)
  ini_file:
    dest: /etc/dnf/dnf.conf
    section: main
    option: localpkg_gpgcheck
    value: 1
    create: true
  when:
    - ansible_distribution == "Fedora"
    - '"yum" in ansible_facts.packages'
  tags:
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - ensure_gpgcheck_local_packages
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed
    - unknown_strategy

Rule   Ensure gpgcheck Enabled for All yum Package Repositories   [ref]

To ensure signature checking is not disabled for any repos, remove any lines from files in /etc/yum.repos.d of the form:
gpgcheck=0
Rationale:
Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA)."
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_gpgcheck_never_disabled
Identifiers and References

References:  SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650, 5.10.4.1, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, 11, 2, 3, 9, BP28(R15)


sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/yum.repos.d/*

Complexity:low
Disruption:medium
Strategy:enable
- name: Grep for yum repo section names
  shell: grep -HEr '^\[.+\]' -r /etc/yum.repos.d/
  register: repo_grep_results
  ignore_errors: true
  changed_when: false
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - enable_strategy
    - ensure_gpgcheck_never_disabled
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed

- name: Set gpgcheck=1 for each yum repo
  ini_file:
    path: '{{ item[0] }}'
    section: '{{ item[1] }}'
    option: gpgcheck
    value: '1'
    no_extra_spaces: true
  loop: '{{ repo_grep_results.stdout | regex_findall( ''(.+\.repo):\[(.+)\]\n?'' )
    }}'
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-11(a)
    - NIST-800-53-CM-11(b)
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SA-12
    - NIST-800-53-SA-12(10)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - enable_strategy
    - ensure_gpgcheck_never_disabled
    - high_severity
    - low_complexity
    - medium_disruption
    - no_reboot_needed

Rule   Ensure Red Hat GPG Key Installed   [ref]

To ensure the system can cryptographically verify base software packages come from Red Hat (and to connect to the Red Hat Network to receive them), the Red Hat GPG key must properly be installed. To install the Red Hat GPG key, run:
$ sudo subscription-manager register
If the system is not connected to the Internet or an RHN Satellite, then install the Red Hat GPG key from trusted media such as the Red Hat installation CD-ROM or DVD. Assuming the disc is mounted in /media/cdrom, use the following command as the root user to import it into the keyring:
$ sudo rpm --import /media/cdrom/RPM-GPG-KEY
Alternatively, the key may be pre-loaded during the RHEL installation. In such cases, the key can be installed by running the following command:
sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
Rationale:
Changes to software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. The Red Hat GPG key is necessary to cryptographically verify packages are from Red Hat.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_redhat_gpgkey_installed
Identifiers and References

References:  SRG-OS-000366-GPOS-00153, SRG-OS-000366-VMM-001430, SRG-OS-000370-VMM-001460, SRG-OS-000404-VMM-001650, 5.10.4.1, 3.4.8, CCI-001749, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, 11, 2, 3, 9, BP28(R15)


# The two fingerprints below are retrieved from https://access.redhat.com/security/team/key
readonly REDHAT_RELEASE_FINGERPRINT="567E347AD0044ADE55BA8A5F199E2F91FD431D51"
readonly REDHAT_AUXILIARY_FINGERPRINT="6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792"

# Location of the key we would like to import (once it's integrity verified)
readonly REDHAT_RELEASE_KEY="/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"

RPM_GPG_DIR_PERMS=$(stat -c %a "$(dirname "$REDHAT_RELEASE_KEY")")

# Verify /etc/pki/rpm-gpg directory permissions are safe
if [ "${RPM_GPG_DIR_PERMS}" -le "755" ]
then
  # If they are safe, try to obtain fingerprints from the key file
  # (to ensure there won't be e.g. CRC error).

  readarray -t GPG_OUT < <(gpg --show-keys --with-fingerprint --with-colons "$REDHAT_RELEASE_KEY" | grep -A1 "^pub" | grep "^fpr" | cut -d ":" -f 10)

  GPG_RESULT=$?
  # No CRC error, safe to proceed
  if [ "${GPG_RESULT}" -eq "0" ]
  then
    echo "${GPG_OUT[*]}" | grep -vE "${REDHAT_RELEASE_FINGERPRINT}|${REDHAT_AUXILIARY_FINGERPRINT}" || {
      # If $REDHAT_RELEASE_KEY file doesn't contain any keys with unknown fingerprint, import it
      rpm --import "${REDHAT_RELEASE_KEY}"
    }
  fi
fi

Complexity:medium
Disruption:medium
Strategy:restrict
- name: Read permission of GPG key directory
  stat:
    path: /etc/pki/rpm-gpg/
  register: gpg_key_directory_permission
  check_mode: false
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Read signatures in GPG key
  command: gpg --with-fingerprint --with-colons "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"
  args:
    warn: false
  changed_when: false
  register: gpg_fingerprints
  check_mode: false
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Set Fact - Installed GPG Fingerprints
  set_fact:
    gpg_installed_fingerprints: |-
      {{ gpg_fingerprints.stdout | regex_findall('^pub.*
      (?:^fpr[:]*)([0-9A-Fa-f]*)', '\1') | list }}
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Set Fact - Valid fingerprints
  set_fact:
    gpg_valid_fingerprints: ("567E347AD0044ADE55BA8A5F199E2F91FD431D51" "6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792")
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy

- name: Import RedHat GPG key
  rpm_key:
    state: present
    key: /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
  when:
    - gpg_key_directory_permission.stat.mode <= '0755'
    - (gpg_installed_fingerprints | difference(gpg_valid_fingerprints)) | length ==
      0
    - gpg_installed_fingerprints | length > 0
    - ansible_distribution == "RedHat"
  tags:
    - CJIS-5.10.4.1
    - NIST-800-171-3.4.8
    - NIST-800-53-CM-5(3)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-12
    - NIST-800-53-SC-12(3)
    - NIST-800-53-SI-7
    - PCI-DSS-Req-6.2
    - ensure_redhat_gpgkey_installed
    - high_severity
    - medium_complexity
    - medium_disruption
    - no_reboot_needed
    - restrict_strategy
Group   Account and Access Control   Group contains 14 groups and 33 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 Red Hat Virtualization 4.
Group   Warning Banners for System Accesses   Group contains 1 rule
[ref]   Each system should expose as little information about itself as possible.

System banners, which are typically displayed just before a login prompt, give out information about the service or the host's operating system. This might include the distribution name and the system kernel version, and the particular version of a network service. This information can assist intruders in gaining access to the system as it can reveal whether the system is running vulnerable software. Most network services can be configured to limit what information is displayed.

Many organizations implement security policies that require a system banner provide notice of the system's ownership, provide warning to unauthorized users, and remind authorized users of their consent to monitoring.

Rule   Modify the System Login Banner   [ref]

To configure the system login banner edit /etc/issue. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.
Rationale:
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_banner_etc_issue
Identifiers and References

References:  3.1.9, CCI-000048, CCI-000050, AC-8(a), AC-8(c), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000023-GPOS-00006, SRG-OS-000024-GPOS-00007, SRG-OS-000023-VMM-000060, SRG-OS-000024-VMM-000070, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 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, DSS05.04, DSS05.10, DSS06.10, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, 1, 12, 15, 16


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


login_banner_text="(N/A)"



# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
login_banner_text=$(echo "$login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
#    (dod_banners contains the long and short banner)
login_banner_text=$(echo "$login_banner_text" | sed 's/^(\(.*\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
login_banner_text=$(echo "$login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
login_banner_text=$(echo "$login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parethesis in the banner, for example).
login_banner_text=$(echo "$login_banner_text" | sed 's/\\//g')
formatted=$(echo "$login_banner_text" | fold -sw 80)

cat <<EOF >/etc/issue
$formatted
EOF

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Protect Accounts by Configuring PAM   Group contains 4 groups and 16 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 http://www.linux-pam.org/Linux-PAM-html/sag-configuration-file.html.
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 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:  5.6.2.2, 3.13.11, CCI-000196, 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-000480-VMM-002000, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0418, 1055, 1402, BP28(R32)


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

AUTH_FILES[0]="/etc/pam.d/system-auth"
AUTH_FILES[1]="/etc/pam.d/password-auth"

for pamFile in "${AUTH_FILES[@]}"
do
	if ! grep -q "^password.*sufficient.*pam_unix.so.*sha512" $pamFile; then
		sed -i --follow-symlinks "/^password.*sufficient.*pam_unix.so/ s/$/ sha512/" $pamFile
	fi
done

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

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 SHA-512 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:  6.3.1, 5.6.2.2, 3.13.11, CCI-000196, 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, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, BP28(R32), 0418, 1055, 1402


# 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

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
    - 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
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - set_password_hashing_algorithm_logindefs

Rule   Set Password Hashing Algorithm in /etc/libuser.conf   [ref]

In /etc/libuser.conf, add or correct the following line in its [defaults] section to ensure the system will use the SHA-512 algorithm for password hashing:
crypt_style = 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 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_libuserconf
Identifiers and References

References:  5.6.2.2, 3.13.11, CCI-000196, 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-000480-VMM-002000, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0418, 1055, 1402


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

LIBUSER_CONF="/etc/libuser.conf"
CRYPT_STYLE_REGEX='[[:space:]]*\[defaults](.*(\n)+)+?[[:space:]]*crypt_style[[:space:]]*'

# Try find crypt_style in [defaults] section. If it is here, then change algorithm to sha512.
# If it isn't here, then add it to [defaults] section.
if grep -qzosP $CRYPT_STYLE_REGEX $LIBUSER_CONF ; then
        sed -i "s/\(crypt_style[[:space:]]*=[[:space:]]*\).*/\1sha512/g" $LIBUSER_CONF
elif grep -qs "\[defaults]" $LIBUSER_CONF ; then
        sed -i "/[[:space:]]*\[defaults]/a crypt_style = sha512" $LIBUSER_CONF
else
        echo -e "[defaults]\ncrypt_style = sha512" >> $LIBUSER_CONF
fi

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

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
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - set_password_hashing_algorithm_libuserconf

- name: Set Password Hashing Algorithm in /etc/libuser.conf
  lineinfile:
    dest: /etc/libuser.conf
    insertafter: ^\s*\[defaults]
    regexp: ^#?crypt_style
    line: crypt_style = sha512
    state: present
    create: true
  when: '"libuser" 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
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
    - set_password_hashing_algorithm_libuserconf
Group   Set Lockouts for Failed Password Attempts   Group contains 5 rules
[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.

Rule   Set Interval For Counting Failed Password Attempts   [ref]

Utilizing pam_faillock.so, the fail_interval directive configures the system to lock out an account after a number of incorrect login attempts within a specified time period. Modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • Add the following line immediately before the pam_unix.so statement in the AUTH section:
    auth required pam_faillock.so preauth silent deny=3 unlock_time=0 fail_interval=900
  • Add the following line immediately after the pam_unix.so statement in the AUTH section:
    auth [default=die] pam_faillock.so authfail deny=3 unlock_time=0 fail_interval=900
    
  • Add the following line immediately before the pam_unix.so statement in the ACCOUNT section:
    account required pam_faillock.so
Rationale:
By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_interval
Identifiers and References

References:  CCI-000044, CCI-002236, CCI-002237, CCI-002238, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SRG-OS-000021-VMM-000050, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 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, DSS05.04, DSS05.10, DSS06.10, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, 1, 12, 15, 16, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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

# include our remediation functions library

var_accounts_passwords_pam_faillock_fail_interval="900"



AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

for pam_file in "${AUTH_FILES[@]}"
do
    # is auth required pam_faillock.so preauth present?
    if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*'"fail_interval"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock.so.*preauth.*silent.*\)\('"fail_interval"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock.so.*preauth.*silent.*/ s/$/ '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        fi
    # auth required pam_faillock.so preauth is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/i auth        required      pam_faillock.so preauth silent '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval" "$pam_file"
    fi
    # is auth default pam_faillock.so authfail present?
    if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*'"fail_interval"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\('"fail_interval"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*[default=die].*pam_faillock.so.*authfail.*/ s/$/ '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        fi
    # auth default pam_faillock.so authfail is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/a auth        [default=die] pam_faillock.so authfail '"fail_interval"'='"$var_accounts_passwords_pam_faillock_fail_interval" "$pam_file"
    fi
    if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
        sed -E -i --follow-symlinks '/^\s*account\s*required\s*pam_unix.so/i account     required      pam_faillock.so' "$pam_file"
    fi
done

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_accounts_passwords_pam_faillock_fail_interval # promote to variable
  set_fact:
    var_accounts_passwords_pam_faillock_fail_interval: !!str 900
  tags:
    - always

- name: Add auth pam_faillock preauth fail_interval before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add fail_interval argument to auth pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock aufthfail fail_interval after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: after
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add fail_interval argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - accounts_passwords_pam_faillock_interval
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Set Deny For Failed Password Attempts   [ref]

To configure the system to lock out accounts after a number of incorrect login attempts using pam_faillock.so, modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • add the following line immediately before the pam_unix.so statement in the AUTH section:
    auth required pam_faillock.so preauth silent deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately after the pam_unix.so statement in the AUTH section:
    auth [default=die] pam_faillock.so authfail deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately before the pam_unix.so statement in the ACCOUNT section:
    account required pam_faillock.so
Rationale:
Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny
Identifiers and References

References:  5.3.2, 5.5.3, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, Req-8.1.6, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SRG-OS-000021-VMM-000050, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 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, DSS05.04, DSS05.10, DSS06.10, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, 1, 12, 15, 16, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_accounts_passwords_pam_faillock_deny="3"



AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

for pam_file in "${AUTH_FILES[@]}"
do
    # is auth required pam_faillock.so preauth present?
    if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*'"deny"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock.so.*preauth.*silent.*\)\('"deny"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock.so.*preauth.*silent.*/ s/$/ '"deny"'='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        fi
    # auth required pam_faillock.so preauth is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/i auth        required      pam_faillock.so preauth silent '"deny"'='"$var_accounts_passwords_pam_faillock_deny" "$pam_file"
    fi
    # is auth default pam_faillock.so authfail present?
    if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*'"deny"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\('"deny"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*[default=die].*pam_faillock.so.*authfail.*/ s/$/ '"deny"'='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        fi
    # auth default pam_faillock.so authfail is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/a auth        [default=die] pam_faillock.so authfail '"deny"'='"$var_accounts_passwords_pam_faillock_deny" "$pam_file"
    fi
    if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
        sed -E -i --follow-symlinks '/^\s*account\s*required\s*pam_unix.so/i account     required      pam_faillock.so' "$pam_file"
    fi
done

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_accounts_passwords_pam_faillock_deny # promote to variable
  set_fact:
    var_accounts_passwords_pam_faillock_deny: !!str 3
  tags:
    - always

- name: Add auth pam_faillock preauth deny before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent deny={{ var_accounts_passwords_pam_faillock_deny
      }}
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add deny argument to auth pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent deny={{ var_accounts_passwords_pam_faillock_deny
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock authfail deny after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail deny={{ var_accounts_passwords_pam_faillock_deny }}
    state: after
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add deny argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    new_type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail deny={{ var_accounts_passwords_pam_faillock_deny }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(a)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.6
    - accounts_passwords_pam_faillock_deny
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Configure the root Account for Failed Password Attempts   [ref]

To configure the system to lock out the root account after a number of incorrect login attempts using pam_faillock.so, modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • Modify the following line in the AUTH section to add even_deny_root:
    auth required pam_faillock.so preauth silent even_deny_root deny=3 unlock_time=0 fail_interval=900
  • Modify the following line in the AUTH section to add even_deny_root:
    auth [default=die] pam_faillock.so authfail even_deny_root deny=3 unlock_time=0 fail_interval=900
Rationale:
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny_root
Identifiers and References

References:  CCI-002238, CM-6(a), AC-7(b), IA-5(c), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 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, DSS05.04, DSS05.10, DSS06.10, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, 1, 12, 15, 16, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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

AUTH_FILES[0]="/etc/pam.d/system-auth"
AUTH_FILES[1]="/etc/pam.d/password-auth"

# This script fixes absence of pam_faillock.so in PAM stack or the
# absense of even_deny_root in pam_faillock.so arguments
# When inserting auth pam_faillock.so entries,
# the entry with preauth argument will be added before pam_unix.so module
# and entry with authfail argument will be added before pam_deny.so module.

# The placement of pam_faillock.so entries will not be changed
# if they are already present

for pamFile in "${AUTH_FILES[@]}"
do
	# if PAM file is missing, system is not using PAM or broken
	if [ ! -f $pamFile ]; then
		continue
	fi

	# is 'auth required' here?
	if grep -q "^auth.*required.*pam_faillock.so.*" $pamFile; then
		# has 'auth required' even_deny_root option?
		if ! grep -q "^auth.*required.*pam_faillock.so.*preauth.*even_deny_root" $pamFile; then
			# even_deny_root is not present
			sed -i --follow-symlinks "s/\(^auth.*required.*pam_faillock.so.*preauth.*\).*/\1 even_deny_root/" $pamFile
		fi
	else
		# no 'auth required', add it
		sed -i --follow-symlinks "/^auth.*pam_unix.so.*/i auth required pam_faillock.so preauth silent even_deny_root" $pamFile
	fi

	# is 'auth [default=die]' here?
	if grep -q "^auth.*\[default=die\].*pam_faillock.so.*" $pamFile; then
		# has 'auth [default=die]' even_deny_root option?
		if ! grep -q "^auth.*\[default=die\].*pam_faillock.so.*authfail.*even_deny_root" $pamFile; then
			# even_deny_root is not present
			sed -i --follow-symlinks "s/\(^auth.*\[default=die\].*pam_faillock.so.*authfail.*\).*/\1 even_deny_root/" $pamFile
		fi
	else
		# no 'auth [default=die]', add it
		sed -i --follow-symlinks "/^auth.*pam_unix.so.*/a auth [default=die] pam_faillock.so authfail silent even_deny_root" $pamFile
	fi
done

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(c)
    - accounts_passwords_pam_faillock_deny_root
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock preauth even_deny_root before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent even_deny_root
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(c)
    - accounts_passwords_pam_faillock_deny_root
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add even_deny_root argument to auth pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent even_deny_root
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(c)
    - accounts_passwords_pam_faillock_deny_root
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock authfail even_deny_root after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail even_deny_root
    state: after
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(c)
    - accounts_passwords_pam_faillock_deny_root
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add even_deny_root argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail even_deny_root
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(c)
    - accounts_passwords_pam_faillock_deny_root
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-5(c)
    - accounts_passwords_pam_faillock_deny_root
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Set Lockout Time for Failed Password Attempts   [ref]

To configure the system to lock out accounts after a number of incorrect login attempts and require an administrator to unlock the account using pam_faillock.so, modify the content of both /etc/pam.d/system-auth and /etc/pam.d/password-auth as follows:

  • add the following line immediately before the pam_unix.so statement in the AUTH section:
    auth required pam_faillock.so preauth silent deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately after the pam_unix.so statement in the AUTH section:
    auth [default=die] pam_faillock.so authfail deny=3 unlock_time=0 fail_interval=900
  • add the following line immediately before the pam_unix.so statement in the ACCOUNT section:
    account required pam_faillock.so
If unlock_time is set to 0, manual intervention by an administrator is required to unlock a user.
Rationale:
Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks. Ensuring that an administrator is involved in unlocking locked accounts draws appropriate attention to such situations.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_unlock_time
Identifiers and References

References:  5.3.2, 5.5.3, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, CM-6(a), AC-7(b), PR.AC-7, FIA_AFL.1, Req-8.1.7, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, SRG-OS-000329-VMM-001180, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 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, DSS05.04, DSS05.10, DSS06.10, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, 1, 12, 15, 16, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_accounts_passwords_pam_faillock_unlock_time="0"



AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")

for pam_file in "${AUTH_FILES[@]}"
do
    # is auth required pam_faillock.so preauth present?
    if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*'"unlock_time"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock.so.*preauth.*silent.*\)\('"unlock_time"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock.so.*preauth.*silent.*/ s/$/ '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        fi
    # auth required pam_faillock.so preauth is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/i auth        required      pam_faillock.so preauth silent '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time" "$pam_file"
    fi
    # is auth default pam_faillock.so authfail present?
    if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
        # is the option set?
        if grep -qE '^\s*auth\s+(\[default=die\])\s+pam_faillock\.so\s+authfail.*'"unlock_time"'=([0-9]*).*$' "$pam_file" ; then
            # just change the value of option to a correct value
            sed -i --follow-symlinks 's/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\('"unlock_time"' *= *\).*/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        # the option is not set.
        else
            # append the option
            sed -i --follow-symlinks '/^auth.*[default=die].*pam_faillock.so.*authfail.*/ s/$/ '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        fi
    # auth default pam_faillock.so authfail is not present, insert the whole line
    else
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix.so.*/a auth        [default=die] pam_faillock.so authfail '"unlock_time"'='"$var_accounts_passwords_pam_faillock_unlock_time" "$pam_file"
    fi
    if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
        sed -E -i --follow-symlinks '/^\s*account\s*required\s*pam_unix.so/i account     required      pam_faillock.so' "$pam_file"
    fi
done

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_accounts_passwords_pam_faillock_unlock_time # promote to variable
  set_fact:
    var_accounts_passwords_pam_faillock_unlock_time: !!str 0
  tags:
    - always

- name: Add auth pam_faillock preauth unlock_time before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: required
    new_module_path: pam_faillock.so
    module_arguments: preauth silent unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add unlock_time argument to pam_faillock preauth
  pamd:
    name: '{{ item }}'
    type: auth
    control: required
    module_path: pam_faillock.so
    module_arguments: preauth silent unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add auth pam_faillock authfail unlock_interval after pam_unix.so
  pamd:
    name: '{{ item }}'
    type: auth
    control: sufficient
    module_path: pam_unix.so
    new_type: auth
    new_control: '[default=die]'
    new_module_path: pam_faillock.so
    module_arguments: authfail unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: after
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add unlock_time argument to auth pam_faillock authfail
  pamd:
    name: '{{ item }}'
    type: auth
    control: '[default=die]'
    module_path: pam_faillock.so
    module_arguments: authfail unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
      }}
    state: args_present
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Add account pam_faillock before pam_unix.so
  pamd:
    name: '{{ item }}'
    type: account
    control: required
    module_path: pam_unix.so
    new_type: account
    new_control: required
    new_module_path: pam_faillock.so
    state: before
  loop:
    - system-auth
    - password-auth
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.5.3
    - NIST-800-171-3.1.8
    - NIST-800-53-AC-7(b)
    - NIST-800-53-CM-6(a)
    - PCI-DSS-Req-8.1.7
    - accounts_passwords_pam_faillock_unlock_time
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Limit Password Reuse   [ref]

Do not allow users to reuse recent passwords. This can be accomplished by using the remember option for the pam_unix or pam_pwhistory PAM modules.

In the file /etc/pam.d/system-auth, append remember=5 to the line which refers to the pam_unix.so or pam_pwhistory.somodule, as shown below:
  • for the pam_unix.so case:
    password sufficient pam_unix.so ...existing_options... remember=5
  • for the pam_pwhistory.so case:
    password requisite pam_pwhistory.so ...existing_options... remember=5
The DoD STIG requirement is 5 passwords.
Rationale:
Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_unix_remember
Identifiers and References

References:  5.3.3, 5.6.2.1.1, 3.5.8, CCI-000200, IA-5(f), IA-5(1)(e), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.5, SRG-OS-000077-GPOS-00045, SRG-OS-000077-VMM-000440, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, BP28(R18)


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


var_password_pam_unix_remember="5"



AUTH_FILES[0]="/etc/pam.d/system-auth"
AUTH_FILES[1]="/etc/pam.d/password-auth"

for pamFile in "${AUTH_FILES[@]}"
do
	if grep -q "remember=" $pamFile; then
		sed -i --follow-symlinks "s/\(^password.*sufficient.*pam_unix.so.*\)\(\(remember *= *\)[^ $]*\)/\1remember=$var_password_pam_unix_remember/" $pamFile
	else
		sed -i --follow-symlinks "/^password[[:space:]]\+sufficient[[:space:]]\+pam_unix.so/ s/$/ remember=$var_password_pam_unix_remember/" $pamFile
	fi
done

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

Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - CJIS-5.6.2.1.1
    - NIST-800-171-3.5.8
    - NIST-800-53-IA-5(1)(e)
    - NIST-800-53-IA-5(f)
    - PCI-DSS-Req-8.2.5
    - accounts_password_pam_unix_remember
    - configure_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
- name: XCCDF Value var_password_pam_unix_remember # promote to variable
  set_fact:
    var_password_pam_unix_remember: !!str 5
  tags:
    - always

- name: Do not allow users to reuse recent passwords - system-auth (change)
  replace:
    dest: /etc/pam.d/system-auth
    regexp: ^(password\s+sufficient\s+pam_unix\.so\s.*remember\s*=\s*)(\S+)(.*)$
    replace: \g<1>{{ var_password_pam_unix_remember }}\g<3>
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.6.2.1.1
    - NIST-800-171-3.5.8
    - NIST-800-53-IA-5(1)(e)
    - NIST-800-53-IA-5(f)
    - PCI-DSS-Req-8.2.5
    - accounts_password_pam_unix_remember
    - configure_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed

- name: Do not allow users to reuse recent passwords - system-auth (add)
  replace:
    dest: /etc/pam.d/system-auth
    regexp: ^password\s+sufficient\s+pam_unix\.so\s(?!.*remember\s*=\s*).*$
    replace: \g<0> remember={{ var_password_pam_unix_remember }}
  when: '"pam" in ansible_facts.packages'
  tags:
    - CJIS-5.6.2.1.1
    - NIST-800-171-3.5.8
    - NIST-800-53-IA-5(1)(e)
    - NIST-800-53-IA-5(f)
    - PCI-DSS-Req-8.2.5
    - accounts_password_pam_unix_remember
    - configure_strategy
    - low_complexity
    - medium_disruption
    - medium_severity
    - no_reboot_needed
Group   Set Password Quality Requirements   Group contains 1 group and 8 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 8 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 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 compromose the password.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
Identifiers and References

References:  6.3.2, 5.6.2.1.1, CCI-000205, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000078-GPOS-00046, SRG-OS-000072-VMM-000390, SRG-OS-000078-VMM-000450, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_password_pam_minlen="15"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^minlen' $var_password_pam_minlen '' '%s = %s'

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

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
    - 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 variable minlen is set accordingly
  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
    - accounts_password_pam_minlen
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure PAM Enforces Password Requirements - Maximum Consecutive Repeating Characters from Same Character Class   [ref]

The pam_pwquality module's maxclassrepeat parameter controls requirements for consecutive repeating characters from the same character class. When set to a positive number, it will reject passwords which contain more than that number of consecutive characters from the same character class. Modify the maxclassrepeat setting in /etc/security/pwquality.conf to equal 4 to prevent a run of (4 + 1) or more identical characters.
Rationale:
Use of a complex password helps to increase the time and resources required to comrpomise 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 a password, the greater the number of possible combinations that need to be tested before the password is compromised.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_maxclassrepeat
Identifiers and References

References:  CCI-000195, 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, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5


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


var_password_pam_maxclassrepeat="4"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^maxclassrepeat' $var_password_pam_maxclassrepeat '' '%s = %s'

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

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_maxclassrepeat
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_password_pam_maxclassrepeat # promote to variable
  set_fact:
    var_password_pam_maxclassrepeat: !!str 4
  tags:
    - always

- name: Ensure PAM variable maxclassrepeat is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*maxclassrepeat
    line: maxclassrepeat = {{ var_password_pam_maxclassrepeat }}
  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_maxclassrepeat
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

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:  CCI-000195, IA-5(c), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5


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


var_password_pam_maxrepeat="3"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^maxrepeat' $var_password_pam_maxrepeat '' '%s = %s'

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

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: Ensure PAM variable maxrepeat is set accordingly
  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

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:  5.6.2.1.1, CCI-000195, 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, SRG-OS-000072-VMM-000390, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5


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


var_password_pam_difok="8"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^difok' $var_password_pam_difok '' '%s = %s'

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

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 variable difok is set accordingly
  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

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

The pam_pwquality module's dcredit parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_pwquality will grant +1 additional length credit for each digit. Modify the dcredit setting in /etc/security/pwquality.conf to require the use of a digit in 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 digits makes password guessing attacks more difficult by ensuring a larger search space.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_dcredit
Identifiers and References

References:  6.3.2, CCI-000194, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000071-GPOS-00039, SRG-OS-000071-VMM-000380, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_password_pam_dcredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^dcredit' $var_password_pam_dcredit '' '%s = %s'

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

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)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_dcredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_password_pam_dcredit # promote to variable
  set_fact:
    var_password_pam_dcredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable dcredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*dcredit
    line: dcredit = {{ var_password_pam_dcredit }}
  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)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_dcredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

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

The pam_pwquality module's ocredit= parameter controls requirements for usage of special (or "other") characters in a password. When set to a negative number, any password will be required to contain that many special characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each special character. Modify the ocredit setting in /etc/security/pwquality.conf to equal -1 to require use of a special character in 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 possble combinations that need to be tested before the password is compromised. Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_ocredit
Identifiers and References

References:  CCI-001619, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000266-GPOS-00101, SRG-OS-000266-VMM-000940, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_password_pam_ocredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^ocredit' $var_password_pam_ocredit '' '%s = %s'

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

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_ocredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_password_pam_ocredit # promote to variable
  set_fact:
    var_password_pam_ocredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable ocredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*ocredit
    line: ocredit = {{ var_password_pam_ocredit }}
  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_ocredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

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

The pam_pwquality module's lcredit parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each lowercase character. Modify the lcredit setting in /etc/security/pwquality.conf to require the use of a lowercase character in 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 possble combinations that need to be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_lcredit
Identifiers and References

References:  CCI-000193, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000070-GPOS-00038, SRG-OS-000070-VMM-000370, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_password_pam_lcredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^lcredit' $var_password_pam_lcredit '' '%s = %s'

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

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)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_lcredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_password_pam_lcredit # promote to variable
  set_fact:
    var_password_pam_lcredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable lcredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*lcredit
    line: lcredit = {{ var_password_pam_lcredit }}
  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)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_lcredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

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

The pam_pwquality module's ucredit= parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each uppercase character. Modify the ucredit setting in /etc/security/pwquality.conf to require the use of an uppercase character in passwords.
Rationale:
Use of a complex password helps to increase the time and resources reuiqred 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.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_ucredit
Identifiers and References

References:  6.3.2, CCI-000192, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_MOF_EXT.1, Req-8.2.3, SRG-OS-000069-GPOS-00037, SRG-OS-000069-VMM-000360, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, BP28(R18)


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


var_password_pam_ucredit="-1"
# Function to replace configuration setting in config file or add the configuration setting if
# it does not exist.
#
# Expects arguments:
#
# config_file:		Configuration file that will be modified
# key:			Configuration option to change
# value:		Value of the configuration option to change
# cce:			The CCE identifier or '@CCENUM@' if no CCE identifier exists
# format:		The printf-like format string that will be given stripped key and value as arguments,
#			so e.g. '%s=%s' will result in key=value subsitution (i.e. without spaces around =)
#
# Optional arugments:
#
# format:		Optional argument to specify the format of how key/value should be
# 			modified/appended in the configuration file. The default is key = value.
#
# Example Call(s):
#
#     With default format of 'key = value':
#     replace_or_append '/etc/sysctl.conf' '^kernel.randomize_va_space' '2' '@CCENUM@'
#
#     With custom key/value format:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' 'disabled' '@CCENUM@' '%s=%s'
#
#     With a variable:
#     replace_or_append '/etc/sysconfig/selinux' '^SELINUX=' $var_selinux_state '@CCENUM@' '%s=%s'
#
function replace_or_append {
  local default_format='%s = %s' case_insensitive_mode=yes sed_case_insensitive_option='' grep_case_insensitive_option=''
  local config_file=$1
  local key=$2
  local value=$3
  local cce=$4
  local format=$5

  if [ "$case_insensitive_mode" = yes ]; then
    sed_case_insensitive_option="i"
    grep_case_insensitive_option="-i"
  fi
  [ -n "$format" ] || format="$default_format"
  # Check sanity of the input
  [ $# -ge "3" ] || { echo "Usage: replace_or_append <config_file_location> <key_to_search> <new_value> [<CCE number or literal '@CCENUM@' if unknown>] [printf-like format, default is '$default_format']" >&2; exit 1; }

  # Test if the config_file is a symbolic link. If so, use --follow-symlinks with sed.
  # Otherwise, regular sed command will do.
  sed_command=('sed' '-i')
  if test -L "$config_file"; then
    sed_command+=('--follow-symlinks')
  fi

  # Test that the cce arg is not empty or does not equal @CCENUM@.
  # If @CCENUM@ exists, it means that there is no CCE assigned.
  if [ -n "$cce" ] && [ "$cce" != '@CCENUM@' ]; then
    cce="${cce}"
  else
    cce="CCE"
  fi

  # 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=$(sed 's/[\^=\$,;+]*//g' <<< "$key")

  # shellcheck disable=SC2059
  printf -v formatted_output "$format" "$stripped_key" "$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 $grep_case_insensitive_option -e "${key}\\>" "$config_file"; then
    "${sed_command[@]}" "s/${key}\\>.*/$formatted_output/g$sed_case_insensitive_option" "$config_file"
  else
    # \n is precaution for case where file ends without trailing newline
    printf '\n# Per %s: Set %s in %s\n' "$cce" "$formatted_output" "$config_file" >> "$config_file"
    printf '%s\n' "$formatted_output" >> "$config_file"
  fi
}
replace_or_append '/etc/security/pwquality.conf' '^ucredit' $var_password_pam_ucredit '' '%s = %s'

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

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)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_ucredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
- name: XCCDF Value var_password_pam_ucredit # promote to variable
  set_fact:
    var_password_pam_ucredit: !!str -1
  tags:
    - always

- name: Ensure PAM variable ucredit is set accordingly
  lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*ucredit
    line: ucredit = {{ var_password_pam_ucredit }}
  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)
    - PCI-DSS-Req-8.2.3
    - accounts_password_pam_ucredit
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy
Group   Protect Physical Console Access   Group contains 2 groups and 7 rules
[ref]   It is impossible to fully protect a system from an attacker with physical access, so securing the space in which the system is located should be considered a necessary step. However, there are some steps which, if taken, make it more difficult for an attacker to quickly or undetectably modify a system from its console.
Group   Configure Screen Locking   Group contains 1 group and 5 rules
[ref]   When a user must temporarily leave an account logged-in, screen locking should be employed to prevent passersby from abusing the account. User education and training is particularly important for screen locking to be effective, and policies can be implemented to reinforce this.

Automatic screen locking is only meant as a safeguard for those cases where a user forgot to lock the screen.
Group   Hardware Tokens for Authentication   Group contains 5 rules

Rule   Install the opensc Package For Multifactor Authentication   [ref]

The opensc package can be installed with the following command:
$ sudo yum install opensc
Rationale:
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device.

Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DoD Common Access Card.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_opensc_installed
Identifiers and References

References:  CCI-001954, CM-6(a), SRG-OS-000375-GPOS-00160, SRG-OS-000376-VMM-001520, 1382, 1384, 1386


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

if ! rpm -q --quiet "opensc" ; then
    yum install -y "opensc"
fi

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

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure opensc is installed
  package:
    name: opensc
    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_opensc_installed

Complexity:low
Disruption:low
Strategy:enable
include install_opensc

class install_opensc {
  package { 'opensc':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable

package --add=opensc

Rule   Install the pcsc-lite package   [ref]

The pcsc-lite package can be installed with the following command:
$ sudo yum install pcsc-lite
Rationale:
The pcsc-lite package must be installed if it is to be available for multifactor authentication using smartcards.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_pcsc-lite_installed
Identifiers and References

References:  CCI-001954, CM-6(a), SRG-OS-000375-GPOS-00160, SRG-OS-000377-VMM-001530, 1382, 1384, 1386


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

if ! rpm -q --quiet "pcsc-lite" ; then
    yum install -y "pcsc-lite"
fi

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

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure pcsc-lite is installed
  package:
    name: pcsc-lite
    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_pcsc-lite_installed

Complexity:low
Disruption:low
Strategy:enable
include install_pcsc-lite

class install_pcsc-lite {
  package { 'pcsc-lite':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable

package --add=pcsc-lite

Rule   Enable the pcscd Service   [ref]

The pcscd service can be enabled with the following command:
$ sudo systemctl enable pcscd.service
Rationale:
Using an authentication device, such as a CAC or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device.

Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification card and the DoD Common Access Card.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_service_pcscd_enabled
Identifiers and References

References:  CCI-001954, IA-2(1), IA-2(2), IA-2(3), IA-2(4), IA-2(6), IA-2(7), IA-2(11), CM-6(a), SRG-OS-000375-GPOS-00160, SRG-OS-000377-VMM-001530, 1382, 1384, 1386


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'
"$SYSTEMCTL_EXEC" start 'pcscd.service'
"$SYSTEMCTL_EXEC" enable 'pcscd.service'

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

Complexity:low
Disruption:low
Strategy:enable
- name: Enable service pcscd
  block:

    - name: Gather the package facts
      package_facts:
        manager: auto

    - name: Enable service pcscd
      service:
        name: pcscd
        enabled: 'yes'
        state: started
      when:
        - '"pcsc-lite" in ansible_facts.packages'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2(1)
    - NIST-800-53-IA-2(11)
    - NIST-800-53-IA-2(2)
    - NIST-800-53-IA-2(3)
    - NIST-800-53-IA-2(4)
    - NIST-800-53-IA-2(6)
    - NIST-800-53-IA-2(7)
    - enable_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - service_pcscd_enabled

Complexity:low
Disruption:low
Strategy:enable
include enable_pcscd

class enable_pcscd {
  service {'pcscd':
    enable => true,
    ensure => 'running',
  }
}

Rule   Configure opensc Smart Card Drivers   [ref]

The OpenSC smart card tool can auto-detect smart card drivers; however, setting the smart card drivers in use by your organization helps to prevent users from using unauthorized smart cards. The default smart card driver for this profile is cac. To configure the OpenSC driver, edit the /etc/opensc-ARCH.conf (where ARCH is the architecture of your operating system) file. Look for a line similar to:
# card_drivers = old, internal;
and change it to:
card_drivers = cac;
Rationale:
Smart card login provides two-factor authentication stronger than that provided by a username and password combination. Smart cards leverage PKI (public key infrastructure) in order to provide and verify credentials. Configuring the smart card driver in use by your organization helps to prevent users from using unauthorized smart cards.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_configure_opensc_card_drivers
Identifiers and References

References:  CCI-000765, CCI-000766, CCI-000767, CCI-000768, CCI-000771, CCI-000772, CCI-000884, IA-2(1), IA-2(2), IA-2(3), IA-2(4), IA-2(6), IA-2(7), IA-2(11), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.3, SRG-OS-000104-GPOS-00051, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000109-GPOS-00056, SRG-OS-000108-GPOS-00055, SRG-OS-000108-GPOS-00057, SRG-OS-000108-GPOS-00058, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, SRG-OS-000376-VMM-001520, 1382, 1384, 1386


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


var_smartcard_drivers="cac"



OPENSC_TOOL="/usr/bin/opensc-tool"

if [ -f "${OPENSC_TOOL}" ]; then
    ${OPENSC_TOOL} -S app:default:card_drivers:$var_smartcard_drivers
fi

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

Complexity:low
Disruption:low
Strategy:configure
- name: XCCDF Value var_smartcard_drivers # promote to variable
  set_fact:
    var_smartcard_drivers: !!str cac
  tags:
    - always

- name: Check existence of opensc conf
  stat:
    path: /etc/opensc-{{ ansible_architecture }}.conf
  register: opensc_conf_cd
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2(1)
    - NIST-800-53-IA-2(11)
    - NIST-800-53-IA-2(2)
    - NIST-800-53-IA-2(3)
    - NIST-800-53-IA-2(4)
    - NIST-800-53-IA-2(6)
    - NIST-800-53-IA-2(7)
    - PCI-DSS-Req-8.3
    - configure_opensc_card_drivers
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed

- name: Configure smartcard driver block
  block:

    - name: Check if card_drivers is defined
      command: /usr/bin/opensc-tool -G app:default:card_drivers
      changed_when: false
      register: card_drivers

    - name: Configure opensc Smart Card Drivers
      command: |
        /usr/bin/opensc-tool -S app:default:card_drivers:{{ var_smartcard_drivers }}
      when:
        - card_drivers.stdout != var_smartcard_drivers
  when:
    - opensc_conf_cd.stat.exists
    - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2(1)
    - NIST-800-53-IA-2(11)
    - NIST-800-53-IA-2(2)
    - NIST-800-53-IA-2(3)
    - NIST-800-53-IA-2(4)
    - NIST-800-53-IA-2(6)
    - NIST-800-53-IA-2(7)
    - PCI-DSS-Req-8.3
    - configure_opensc_card_drivers
    - configure_strategy
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed

Rule   Force opensc To Use Defined Smart Card Driver   [ref]

The OpenSC smart card tool can auto-detect smart card drivers; however by forcing the smart card driver in use by your organization, opensc will no longer autodetect or use other drivers unless specified. This helps to prevent users from using unauthorized smart cards. The default smart card driver for this profile is cac. To force the OpenSC driver, edit the /etc/opensc-ARCH.conf (where ARCH is the architecture of your operating system) file. Look for a line similar to:
# force_card_driver = customcos;
and change it to:
force_card_driver = cac;
Rationale:
Smart card login provides two-factor authentication stronger than that provided by a username and password combination. Smart cards leverage PKI (public key infrastructure) in order to provide and verify credentials. Forcing the smart card driver in use by your organization helps to prevent users from using unauthorized smart cards.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_force_opensc_card_drivers
Identifiers and References

References:  CCI-000765, CCI-000766, CCI-000767, CCI-000768, CCI-000771, CCI-000772, CCI-000884, IA-2(1), IA-2(2), IA-2(3), IA-2(4), IA-2(6), IA-2(7), IA-2(11), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.3, SRG-OS-000104-GPOS-00051, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000109-GPOS-00056, SRG-OS-000108-GPOS-00055, SRG-OS-000108-GPOS-00057, SRG-OS-000108-GPOS-00058, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, SRG-OS-000376-VMM-001520, 1382, 1384, 1386


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


var_smartcard_drivers="cac"



OPENSC_TOOL="/usr/bin/opensc-tool"

if [ -f "${OPENSC_TOOL}" ]; then
    ${OPENSC_TOOL} -S app:default:force_card_driver:$var_smartcard_drivers
fi

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

Complexity:low
Disruption:low
Strategy:configure
- name: XCCDF Value var_smartcard_drivers # promote to variable
  set_fact:
    var_smartcard_drivers: !!str cac
  tags:
    - always

- name: Check existence of opensc conf
  stat:
    path: /etc/opensc-{{ ansible_architecture }}.conf
  register: opensc_conf_fcd
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2(1)
    - NIST-800-53-IA-2(11)
    - NIST-800-53-IA-2(2)
    - NIST-800-53-IA-2(3)
    - NIST-800-53-IA-2(4)
    - NIST-800-53-IA-2(6)
    - NIST-800-53-IA-2(7)
    - PCI-DSS-Req-8.3
    - configure_strategy
    - force_opensc_card_drivers
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed

- name: Force smartcard driver block
  block:

    - name: Check if force_card_driver is defined
      command: /usr/bin/opensc-tool -G app:default:force_card_driver
      changed_when: false
      register: force_card_driver

    - name: Force opensc To Use Defined Smart Card Driver
      command: |
        /usr/bin/opensc-tool -S app:default:force_card_driver:{{ var_smartcard_drivers }}
      when:
        - force_card_driver.stdout != var_smartcard_drivers
  when:
    - opensc_conf_fcd.stat.exists
    - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2(1)
    - NIST-800-53-IA-2(11)
    - NIST-800-53-IA-2(2)
    - NIST-800-53-IA-2(3)
    - NIST-800-53-IA-2(4)
    - NIST-800-53-IA-2(6)
    - NIST-800-53-IA-2(7)
    - PCI-DSS-Req-8.3
    - configure_strategy
    - force_opensc_card_drivers
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed

Rule   Verify that Interactive Boot is Disabled   [ref]

Red Hat Virtualization 4 systems support an "interactive boot" option that can be used to prevent services from being started. On a Red Hat Virtualization 4 system, interactive boot can be enabled by providing a 1, yes, true, or on value to the systemd.confirm_spawn kernel argument in /etc/default/grub. Remove any instance of
systemd.confirm_spawn=(1|yes|true|on)
from the kernel arguments in that file to disable interactive boot. It is also required to change the runtime configuration, run:
/sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"
Rationale:
Using interactive boot, the console user could disable auditing, firewalls, or other services, weakening system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_disable_interactive_boot
Identifiers and References

References:  3.1.2, 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), SC-2(1), CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_UAU.1, 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, 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, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 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, 11, 12, 14, 15, 16, 18, 3, 5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common; then

CONFIRM_SPAWN_YES="systemd.confirm_spawn=\(1\|yes\|true\|on\)"
CONFIRM_SPAWN_NO="systemd.confirm_spawn=no"

if grep -q "\(GRUB_CMDLINE_LINUX\|GRUB_CMDLINE_LINUX_DEFAULT\)" /etc/default/grub
then
	sed -i "s/${CONFIRM_SPAWN_YES}/${CONFIRM_SPAWN_NO}/" /etc/default/grub
fi
# Remove 'systemd.confirm_spawn' kernel argument also from runtime settings
/sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"

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

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
    - NIST-800-171-3.1.2
    - NIST-800-171-3.4.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-2(1)
    - grub2_disable_interactive_boot
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Verify that Interactive Boot is Disabled in /etc/default/grub
  replace:
    dest: /etc/default/grub
    regexp: systemd.confirm_spawn=(1|yes|true|on)
    replace: systemd.confirm_spawn=no
  when: '"grub2-common" in ansible_facts.packages'
  tags:
    - NIST-800-171-3.1.2
    - NIST-800-171-3.4.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-2(1)
    - grub2_disable_interactive_boot
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Verify that Interactive Boot is Disabled (runtime)
  command: /sbin/grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn"
  when: '"grub2-common" in ansible_facts.packages'
  tags:
    - NIST-800-171-3.1.2
    - NIST-800-171-3.4.5
    - NIST-800-53-CM-6(a)
    - NIST-800-53-SC-2(1)
    - grub2_disable_interactive_boot
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

Rule   Require Authentication for Single User Mode   [ref]

Single-user mode is intended as a system recovery method, providing a single user root access to the system by providing a boot option at startup. By default, no authentication is performed if single-user mode is selected.

By default, single-user mode is protected by requiring a password and is set in /usr/lib/systemd/system/rescue.service.
Rationale:
This prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_require_singleuser_auth
Identifiers and References

References:  3.1.1, 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), IA-2, AC-3, 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, 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, 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, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 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, 1, 11, 12, 14, 15, 16, 18, 3, 5, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561


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

service_file="/usr/lib/systemd/system/rescue.service"

sulogin='/bin/sh -c "/sbin/sulogin; /usr/bin/systemctl --fail --no-block default"'

if grep "^ExecStart=.*" "$service_file" ; then
    sed -i "s%^ExecStart=.*%ExecStart=-$sulogin%" "$service_file"
else
    echo "ExecStart=-$sulogin" >> "$service_file"
fi

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

Complexity:low
Disruption:low
Strategy:restrict
- name: require single user mode password
  lineinfile:
    create: true
    dest: /usr/lib/systemd/system/rescue.service
    regexp: ^#?ExecStart=
    line: ExecStart=-/bin/sh -c "/sbin/sulogin; /usr/bin/systemctl --fail --no-block
      default"
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-171-3.1.1
    - NIST-800-171-3.4.5
    - NIST-800-53-AC-3
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - require_singleuser_auth
    - restrict_strategy
Group   Protect Accounts by Restricting Password-Based Login   Group contains 4 groups and 9 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   Restrict Root Logins   Group contains 5 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   Restrict Serial Port Root Logins   [ref]

To restrict root logins on serial ports, ensure lines of this form do not appear in /etc/securetty:
ttyS0
ttyS1
Rationale:
Preventing direct root login to serial port interfaces helps ensure accountability for actions taken on the systems using the root account.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_restrict_serial_port_logins
Identifiers and References

References:  3.1.1, 3.1.5, CCI-000770, 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-6, CM-6(a), PR.AC-4, PR.DS-5, SR 2.1, SR 5.2, 4.3.3.7.3, APO01.06, DSS05.04, DSS05.07, DSS06.02, 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, 12, 13, 14, 15, 16, 18, 3, 5


sed -i '/ttyS/d' /etc/securetty

Complexity:low
Disruption:low
Strategy:restrict
- name: Restrict Serial Port Root Logins
  lineinfile:
    dest: /etc/securetty
    regexp: ttyS[0-9]
    state: absent
  tags:
    - NIST-800-171-3.1.1
    - NIST-800-171-3.1.5
    - NIST-800-53-AC-6
    - NIST-800-53-CM-6(a)
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_serial_port_logins
    - restrict_strategy

Rule   Ensure that System Accounts Are Locked   [ref]

Some accounts are not associated with a human user of the system, and exist to perform some administrative function. An attacker should not be able to log into these accounts.

System accounts are those user accounts with a user ID less than UID_MIN, where value of the UID_MIN directive is set in /etc/login.defs configuration file. In the default configuration UID_MIN is set to 500, thus system accounts are those user accounts with a user ID less than 500. If any system account SYSACCT (other than root) has an unlocked password, disable it with the command:
$ sudo passwd -l SYSACCT
Rationale:
Disabling authentication for default system accounts makes it more difficult for attackers to make use of them to compromise a system.false
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_password_auth_for_systemaccounts
Identifiers and References

References:  AC-6, CM-6(a)

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:  3.1.1, 3.1.5, CCI-000366, IA-2, AC-6(5), IA-4(b), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, SRG-OS-000480-GPOS-00227, 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, 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, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 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, 1, 12, 13, 14, 15, 16, 18, 3, 5


awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs --max-lines=1 passwd -l

Rule   Direct root Logins Not Allowed   [ref]

To further limit access to the root account, administrators can disable root logins at the console by editing the /etc/securetty file. This file lists all devices the root user is allowed to login to. If the file does not exist at all, the root user can login through any communication device on the system, whether via the console or via a raw network interface. This is dangerous as user can login to the system as root via Telnet, which sends the password in plain text over the network. By default, Red Hat Virtualization 4's /etc/securetty file only allows the root user to login at the console physically attached to the system. To prevent root from logging in, remove the contents of this file. To prevent direct root logins, remove the contents of this file by typing the following command:
$ sudo echo > /etc/securetty
Rationale:
Disabling direct root logins ensures proper accountability and multifactor authentication to privileged accounts. Users will first login, then escalate to privileged (root) access via su / sudo. This is required for FISMA Low and FISMA Moderate systems.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_direct_root_logins
Identifiers and References

References:  3.1.1, 3.1.6, 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), IA-2, CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, 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, 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, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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, 1, 12, 15, 16, 5, BP28(R19)


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

echo > /etc/securetty

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Direct root Logins Not Allowed
  copy:
    dest: /etc/securetty
    content: ''
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - NIST-800-171-3.1.1
    - NIST-800-171-3.1.6
    - NIST-800-53-CM-6(a)
    - NIST-800-53-IA-2
    - low_complexity
    - low_disruption
    - medium_severity
    - no_direct_root_logins
    - no_reboot_needed
    - restrict_strategy
Group   Set Account Expiration Parameters   Group contains 1 rule
Group   Verify Proper Storage and Existence of Password Hashes   Group contains 1 rule
[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   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 to prevent logins with empty passwords.
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:  5.5.2, 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), 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, SRG-OS-000480-GPOS-00227, 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, 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, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 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, 1, 12, 13, 14, 15, 16, 18, 3, 5


sed --follow-symlinks -i 's/\<nullok\>//g' /etc/pam.d/system-auth
sed --follow-symlinks -i 's/\<nullok\>//g' /etc/pam.d/password-auth

Complexity:low
Disruption:medium
Strategy:configure
- name: Prevent Log In to Accounts With Empty Password - system-auth
  replace:
    dest: /etc/pam.d/system-auth
    regexp: nullok
  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
    - configure_strategy
    - high_severity
    - low_complexity
    - medium_disruption
    - no_empty_passwords
    - no_reboot_needed

- name: Prevent Log In to Accounts With Empty Password - password-auth
  replace:
    dest: /etc/pam.d/password-auth
    regexp: nullok
  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
    - configure_strategy
    - high_severity
    - low_complexity
    - medium_disruption
    - no_empty_passwords
    - no_reboot_needed

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
      - contents:
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        mode: 0644
        path: /etc/pam.d/password-auth
        overwrite: true
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        mode: 0644
        path: /etc/pam.d/system-auth
        overwrite: true
Group   Set Password Expiration Parameters   Group contains 2 rules
[ref]   The file /etc/login.defs controls several password-related settings. Programs such as passwd, su, and login consult /etc/login.defs to determine behavior with regard to password aging, expiration warnings, and length. See the man page login.defs(5) for more information.

Users should be forced to change their passwords, in order to decrease the utility of compromised passwords. However, the need to change passwords often should be balanced against the risk that users will reuse or write down passwords if forced to change them too often. Forcing password changes every 90-360 days, depending on the environment, is recommended. Set the appropriate value as PASS_MAX_DAYS and apply it to existing accounts with the -M flag.

The PASS_MIN_DAYS (-m) setting prevents password changes for 7 days after the first change, to discourage password cycling. If you use this setting, train users to contact an administrator for an emergency password change in case a new password becomes compromised. The PASS_WARN_AGE (-W) setting gives users 7 days of warnings at login time that their passwords are about to expire.

For example, for each existing human user USER, expiration parameters could be adjusted to a 180 day maximum password age, 7 day minimum password age, and 7 day warning period with the following command:
$ sudo chage -M 180 -m 7 -W 7 USER
Group   System Accounting with auditd   Group contains 8 groups and 63 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 Fedora Documentation available at https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/SELinux_Users_and_Administrators_Guide/sect-Security-Enhanced_Linux-Troubleshooting-Fixing_Problems.html#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 7 groups and 61 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 File Deletion Events by User   Group contains 5 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:  5.2.14, 3.1.7, 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), 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, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000392-GPOS-00172, SRG-OS-000466-VMM-001870, SRG-OS-000468-VMM-001890, 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, 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, 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, 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, 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9


# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; 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 "${RULE_ARCHS[@]}"
do
	PATTERN="-a always,exit -F arch=$ARCH -S rename.*"
	GROUP="delete"
	FULL_RULE="-a always,exit -F arch=$ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
	fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
	fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
done

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

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Set architecture for audit rename tasks
  set_fact:
    audit_arch: b{{ ansible_architecture | regex_replace('.*(\d\d$)','\1') }}
  when: 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Search /etc/audit/rules.d for other DAC audit rules
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: -F key=delete$
    patterns: '*.rules'
  register: find_rename
  when: 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: If existing DAC ruleset not found, use /etc/audit/rules.d/delete.rules as
    the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/delete.rules
  when:
    - find_rename.matched is defined and find_rename.matched == 0
    - 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
    - audit_rules_file_deletion_events_rename
    - 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_rename.files | map(attribute=''path'') | list | first }}'
  when:
    - find_rename.matched is defined and find_rename.matched > 0
    - 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rename rule in rules.d when on x86
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b32 -S rename -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when: 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rename rule in rules.d when on x86_64
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b64 -S rename -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rename rule in /etc/audit/audit.rules when on x86
  lineinfile:
    line: -a always,exit -F arch=b32 -S rename -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when: 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rename rule in audit.rules when on x86_64
  lineinfile:
    line: -a always,exit -F arch=b64 -S rename -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_rename
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

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:  5.2.14, 3.1.7, 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), 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, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000392-GPOS-00172, SRG-OS-000466-VMM-001870, SRG-OS-000468-VMM-001890, 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, 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, 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, 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, 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9


# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; 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 "${RULE_ARCHS[@]}"
do
	PATTERN="-a always,exit -F arch=$ARCH -S renameat.*"
	GROUP="delete"
	FULL_RULE="-a always,exit -F arch=$ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
	fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
	fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
done

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

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Set architecture for audit renameat tasks
  set_fact:
    audit_arch: b{{ ansible_architecture | regex_replace('.*(\d\d$)','\1') }}
  when: 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Search /etc/audit/rules.d for other DAC audit rules
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: -F key=delete$
    patterns: '*.rules'
  register: find_renameat
  when: 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: If existing DAC ruleset not found, use /etc/audit/rules.d/delete.rules as
    the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/delete.rules
  when:
    - find_renameat.matched is defined and find_renameat.matched == 0
    - 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
    - audit_rules_file_deletion_events_renameat
    - 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_renameat.files | map(attribute=''path'') | list | first }}'
  when:
    - find_renameat.matched is defined and find_renameat.matched > 0
    - 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the renameat rule in rules.d when on x86
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b32 -S renameat -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when: 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the renameat rule in rules.d when on x86_64
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b64 -S renameat -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the renameat rule in /etc/audit/audit.rules when on x86
  lineinfile:
    line: -a always,exit -F arch=b32 -S renameat -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when: 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the renameat rule in audit.rules when on x86_64
  lineinfile:
    line: -a always,exit -F arch=b64 -S renameat -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_renameat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

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:  5.2.14, 3.1.7, 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), 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, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000392-GPOS-00172, SRG-OS-000466-VMM-001870, SRG-OS-000468-VMM-001890, 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, 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, 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, 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, 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9


# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; 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 "${RULE_ARCHS[@]}"
do
	PATTERN="-a always,exit -F arch=$ARCH -S unlinkat.*"
	GROUP="delete"
	FULL_RULE="-a always,exit -F arch=$ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
	fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
	fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
done

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

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Set architecture for audit unlinkat tasks
  set_fact:
    audit_arch: b{{ ansible_architecture | regex_replace('.*(\d\d$)','\1') }}
  when: 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Search /etc/audit/rules.d for other DAC audit rules
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: -F key=delete$
    patterns: '*.rules'
  register: find_unlinkat
  when: 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: If existing DAC ruleset not found, use /etc/audit/rules.d/delete.rules as
    the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/delete.rules
  when:
    - find_unlinkat.matched is defined and find_unlinkat.matched == 0
    - 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
    - audit_rules_file_deletion_events_unlinkat
    - 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_unlinkat.files | map(attribute=''path'') | list | first }}'
  when:
    - find_unlinkat.matched is defined and find_unlinkat.matched > 0
    - 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the unlinkat rule in rules.d when on x86
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b32 -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when: 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the unlinkat rule in rules.d when on x86_64
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b64 -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the unlinkat rule in /etc/audit/audit.rules when on x86
  lineinfile:
    line: -a always,exit -F arch=b32 -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when: 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the unlinkat rule in audit.rules when on x86_64
  lineinfile:
    line: -a always,exit -F arch=b64 -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_unlinkat
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

Rule   Ensure auditd Collects File Deletion Events by User - rmdir   [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 -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 -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_rmdir
Identifiers and References

References:  5.2.14, 3.1.7, 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), 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, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000392-GPOS-00172, SRG-OS-000466-VMM-001870, SRG-OS-000468-VMM-001890, 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, 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, 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, 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, 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9


# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; 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 "${RULE_ARCHS[@]}"
do
	PATTERN="-a always,exit -F arch=$ARCH -S rmdir.*"
	GROUP="delete"
	FULL_RULE="-a always,exit -F arch=$ARCH -S rmdir -F auid>=1000 -F auid!=unset -F key=delete"
	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
	fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
	fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
done

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

Complexity:low
Disruption:low
Reboot:true
Strategy:restrict
- name: Set architecture for audit rmdir tasks
  set_fact:
    audit_arch: b{{ ansible_architecture | regex_replace('.*(\d\d$)','\1') }}
  when: 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Search /etc/audit/rules.d for other DAC audit rules
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: -F key=delete$
    patterns: '*.rules'
  register: find_rmdir
  when: 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: If existing DAC ruleset not found, use /etc/audit/rules.d/delete.rules as
    the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/delete.rules
  when:
    - find_rmdir.matched is defined and find_rmdir.matched == 0
    - 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
    - audit_rules_file_deletion_events_rmdir
    - 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_rmdir.files | map(attribute=''path'') | list | first }}'
  when:
    - find_rmdir.matched is defined and find_rmdir.matched > 0
    - 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rmdir rule in rules.d when on x86
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b32 -S rmdir -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when: 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rmdir rule in rules.d when on x86_64
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F arch=b64 -S rmdir -F auid>=1000 -F auid!=unset -F key=delete
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rmdir rule in /etc/audit/audit.rules when on x86
  lineinfile:
    line: -a always,exit -F arch=b32 -S rmdir -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when: 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy

- name: Inserts/replaces the rmdir rule in audit.rules when on x86_64
  lineinfile:
    line: -a always,exit -F arch=b64 -S rmdir -F auid>=1000 -F auid!=unset -F key=delete
    state: present
    dest: /etc/audit/audit.rules
    create: true
  when:
    - audit_arch is defined and audit_arch == 'b64'
    - 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
    - audit_rules_file_deletion_events_rmdir
    - low_complexity
    - low_disruption
    - medium_severity
    - reboot_required
    - restrict_strategy
Group   Record Information on the Use of Privileged Commands   Group contains 17 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 - umount   [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/bin/umount -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/bin/umount -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_umount
Identifiers and References

References:  3.1.7, CCI-000135, 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), 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, SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215, SRG-OS-000471-VMM-001910, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, 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, 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, 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, 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9


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



PATTERN="-a always,exit -F path=/usr/bin/umount\\s\\+.*"
GROUP="privileged"
# Although the fix doesn't use ARCH, we reset it because it could have been set by some other remediation
ARCH=""
FULL_RULE="-a always,exit -F path=/usr/bin/umount -F auid>=1000 -F auid!=unset -F key=privileged"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Search /etc/audit/rules.d for audit rule entries
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: ^.*path=/usr/bin/umount.*$
    patterns: '*.rules'
  register: find_umount
  when: 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_privileged_commands_umount
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Use /etc/audit/rules.d/privileged.rules as the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/privileged.rules
  when:
    - find_umount.matched is defined and find_umount.matched == 0
    - 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_privileged_commands_umount
    - 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_umount.files | map(attribute=''path'') | list | first }}'
  when:
    - find_umount.matched is defined and find_umount.matched > 0
    - 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_privileged_commands_umount
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Inserts/replaces the umount rule in rules.d
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F path=/usr/bin/umount -F auid>=1000 -F auid!=unset -F key=privileged
    create: true
  when: 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_privileged_commands_umount
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Inserts/replaces the umount rule in audit.rules
  lineinfile:
    path: /etc/audit/audit.rules
    line: -a always,exit -F path=/usr/bin/umount -F auid>=1000 -F auid!=unset -F key=privileged
    create: true
  when: 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_privileged_commands_umount
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure auditd Collects Information on the Use of Privileged Commands - gpasswd   [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/bin/gpasswd -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/bin/gpasswd -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_gpasswd
Identifiers and References

References:  3.1.7, CCI-000135, 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), AC-2(4), 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215, SRG-OS-000471-VMM-001910, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, 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, 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, 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, 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9


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



PATTERN="-a always,exit -F path=/usr/bin/gpasswd\\s\\+.*"
GROUP="privileged"
# Although the fix doesn't use ARCH, we reset it because it could have been set by some other remediation
ARCH=""
FULL_RULE="-a always,exit -F path=/usr/bin/gpasswd -F auid>=1000 -F auid!=unset -F key=privileged"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Search /etc/audit/rules.d for audit rule entries
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: ^.*path=/usr/bin/gpasswd.*$
    patterns: '*.rules'
  register: find_gpasswd
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - 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)
    - audit_rules_privileged_commands_gpasswd
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Use /etc/audit/rules.d/privileged.rules as the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/privileged.rules
  when:
    - find_gpasswd.matched is defined and find_gpasswd.matched == 0
    - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - 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)
    - audit_rules_privileged_commands_gpasswd
    - 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_gpasswd.files | map(attribute=''path'') | list | first }}'
  when:
    - find_gpasswd.matched is defined and find_gpasswd.matched > 0
    - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - 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)
    - audit_rules_privileged_commands_gpasswd
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Inserts/replaces the gpasswd rule in rules.d
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F path=/usr/bin/gpasswd -F auid>=1000 -F auid!=unset -F
      key=privileged
    create: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - 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)
    - audit_rules_privileged_commands_gpasswd
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Inserts/replaces the gpasswd rule in audit.rules
  lineinfile:
    path: /etc/audit/audit.rules
    line: -a always,exit -F path=/usr/bin/gpasswd -F auid>=1000 -F auid!=unset -F
      key=privileged
    create: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
    - 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)
    - audit_rules_privileged_commands_gpasswd
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure auditd Collects Information on the Use of Privileged Commands - sudo   [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/bin/sudo -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/bin/sudo -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_sudo
Identifiers and References

References:  3.1.7, CCI-000130, CCI-000135, 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), 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-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-VMM-001910, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, 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, 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, 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, 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, BP28(R19)


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



PATTERN="-a always,exit -F path=/usr/bin/sudo\\s\\+.*"
GROUP="privileged"
# Although the fix doesn't use ARCH, we reset it because it could have been set by some other remediation
ARCH=""
FULL_RULE="-a always,exit -F path=/usr/bin/sudo -F auid>=1000 -F auid!=unset -F key=privileged"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# -----------------------------------------------------------------------------------------
#
declare -a files_to_inspect

retval=0

# First check sanity of the specified audit tool
if [ "$tool" != 'auditctl' ] && [ "$tool" != 'augenrules' ]
then
	echo "Unknown audit rules loading tool: $1. Aborting."
	echo "Use either 'auditctl' or 'augenrules'!"
	return 1
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
elif [ "$tool" == 'auditctl' ]
then
	files_to_inspect+=('/etc/audit/audit.rules' )
# 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/$key.rules' to the list for inspection
elif [ "$tool" == 'augenrules' ]
then
	# Extract audit $key from audit rule so we can use it later
	matches=()
	key=$(expr "$full_rule" : '.*-k[[:space:]]\([^[:space:]]\+\)' '|' "$full_rule" : '.*-F[[:space:]]key=\([^[:space:]]\+\)')
	readarray -t matches < <(sed -s -n -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d;F" /etc/audit/rules.d/*.rules)
	if [ $? -ne 0 ]
	then
		retval=1
	fi
	for match in "${matches[@]}"
	do
		files_to_inspect+=("${match}")
	done
	# 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
fi

#
# Indicator that we want to append $full_rule into $audit_file by default
local append_expected_rule=0

for audit_file in "${files_to_inspect[@]}"
do
	# Filter existing $audit_file rules' definitions to select those that:
	# * follow the rule pattern, and
	# * meet the hardware architecture requirement, and
	# * are current syscall group specific
	readarray -t existing_rules < <(sed -e "\;${pattern};!d" -e "/${arch}/!d" -e "/${group}/!d"  "$audit_file")
	if [ $? -ne 0 ]
	then
		retval=1
	fi

	# Process rules found case-by-case
	for rule in "${existing_rules[@]}"
	do
		# Found rule is for same arch & key, but differs (e.g. in count of -S arguments)
		if [ "${rule}" != "${full_rule}" ]
		then
			# If so, isolate just '(-S \w)+' substring of that rule
			rule_syscalls=$(echo "$rule" | grep -o -P '(-S \w+ )+')
			# Check if list of '-S syscall' arguments of that rule is subset
			# of '-S syscall' list of expected $full_rule
			if grep -q -- "$rule_syscalls" <<< "$full_rule"
			then
				# Rule is covered (i.e. the list of -S syscalls for this rule is
				# subset of -S syscalls of $full_rule => existing rule can be deleted
				# Thus delete the rule from audit.rules & our array
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi
				existing_rules=("${existing_rules[@]//$rule/}")
			else
				# Rule isn't covered by $full_rule - it besides -S syscall arguments
				# for this group contains also -S syscall arguments for other syscall
				# group. Example: '-S lchown -S fchmod -S fchownat' => group='chown'
				# since 'lchown' & 'fchownat' share 'chown' substring
				# Therefore:
				# * 1) delete the original rule from audit.rules
				# (original '-S lchown -S fchmod -S fchownat' rule would be deleted)
				# * 2) delete the -S syscall arguments for this syscall group, but
				# keep those not belonging to this syscall group
				# (original '-S lchown -S fchmod -S fchownat' would become '-S fchmod'
				# * 3) append the modified (filtered) rule again into audit.rules
				# if the same rule not already present
				#
				# 1) Delete the original rule
				sed -i -e "\;${rule};d" "$audit_file"
				if [ $? -ne 0 ]
				then
					retval=1
				fi

				# 2) Delete syscalls for this group, but keep those from other groups
				# Convert current rule syscall's string into array splitting by '-S' delimiter
				IFS_BKP="$IFS"
				IFS=$'-S'
				read -a rule_syscalls_as_array <<< "$rule_syscalls"
				# Reset IFS back to default
				IFS="$IFS_BKP"
				# Splitting by "-S" can't be replaced by the readarray functionality easily

				# Declare new empty string to hold '-S syscall' arguments from other groups
				new_syscalls_for_rule=''
				# Walk through existing '-S syscall' arguments
				for syscall_arg in "${rule_syscalls_as_array[@]}"
				do
					# Skip empty $syscall_arg values
					if [ "$syscall_arg" == '' ]
					then
						continue
					fi
					# If the '-S syscall' doesn't belong to current group add it to the new list
					# (together with adding '-S' delimiter back for each of such item found)
					if grep -q -v -- "$group" <<< "$syscall_arg"
					then
						new_syscalls_for_rule="$new_syscalls_for_rule -S $syscall_arg"
					fi
				done
				# Replace original '-S syscall' list with the new one for this rule
				updated_rule=${rule//$rule_syscalls/$new_syscalls_for_rule}
				# Squeeze repeated whitespace characters in rule definition (if any) into one
				updated_rule=$(echo "$updated_rule" | tr -s '[:space:]')
				# 3) Append the modified / filtered rule again into audit.rules
				#    (but only in case it's not present yet to prevent duplicate definitions)
				if ! grep -q -- "$updated_rule" "$audit_file"
				then
					echo "$updated_rule" >> "$audit_file"
				fi
			fi
		else
			# $audit_file already contains the expected rule form for this
			# architecture & key => don't insert it second time
			append_expected_rule=1
		fi
	done

	# We deleted all rules that were subset of the expected one for this arch & key.
	# Also isolated rules containing system calls not from this system calls group.
	# Now append the expected rule if it's not present in $audit_file yet
	if [[ ${append_expected_rule} -eq "0" ]]
	then
		echo "$full_rule" >> "$audit_file"
	fi
done

return $retval

}
fix_audit_syscall_rule "auditctl" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"
fix_audit_syscall_rule "augenrules" "$PATTERN" "$GROUP" "$ARCH" "$FULL_RULE"

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

Complexity:low
Disruption:low
Strategy:restrict
- name: Search /etc/audit/rules.d for audit rule entries
  find:
    paths: /etc/audit/rules.d
    recurse: false
    contains: ^.*path=/usr/bin/sudo.*$
    patterns: '*.rules'
  register: find_sudo
  when: 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_privileged_commands_sudo
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Use /etc/audit/rules.d/privileged.rules as the recipient for the rule
  set_fact:
    all_files:
      - /etc/audit/rules.d/privileged.rules
  when:
    - find_sudo.matched is defined and find_sudo.matched == 0
    - 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_privileged_commands_sudo
    - 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_sudo.files | map(attribute=''path'') | list | first }}'
  when:
    - find_sudo.matched is defined and find_sudo.matched > 0
    - 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_privileged_commands_sudo
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Inserts/replaces the sudo rule in rules.d
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -a always,exit -F path=/usr/bin/sudo -F auid>=1000 -F auid!=unset -F key=privileged
    create: true
  when: 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_privileged_commands_sudo
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

- name: Inserts/replaces the sudo rule in audit.rules
  lineinfile:
    path: /etc/audit/audit.rules
    line: -a always,exit -F path=/usr/bin/sudo -F auid>=1000 -F auid!=unset -F key=privileged
    create: true
  when: 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_privileged_commands_sudo
    - low_complexity
    - low_disruption
    - medium_severity
    - no_reboot_needed
    - restrict_strategy

Rule   Ensure auditd Collects Information on the Use of Privileged Commands - sudoedit   [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/bin/sudoedit -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/bin/sudoedit -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_sudoedit
Identifiers and References

References:  3.1.7, CCI-000135, 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), 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-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215, SRG-OS-000471-VMM-001910, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, 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, 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, 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, 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9


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



PATTERN="-a always,exit -F path=/usr/bin/sudoedit\\s\\+.*"
GROUP="privileged"
# Although the fix doesn't use ARCH, we reset it because it could have been set by some other remediation
ARCH=""
FULL_RULE="-a always,exit -F path=/usr/bin/sudoedit -F auid>=1000 -F auid!=unset -F key=privileged"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Function to fix syscall audit rule for given system call. It is
# based on example audit syscall rule definitions as outlined in
# /usr/share/doc/audit-2.3.7/stig.rules file provided with the audit
# package. It will combine multiple system calls belonging to the same
# syscall group into one audit rule (rather than to create audit rule per
# different system call) to avoid audit infrastructure performance penalty
# in the case of 'one-audit-rule-definition-per-one-system-call'. See:
#
#   https://www.redhat.com/archives/linux-audit/2014-November/msg00009.html
#
# for further details.
#
# Expects five arguments (each of them is required) in the form of:
# * audit tool				tool used to load audit rules,
# 					either 'auditctl', or 'augenrules
# * audit rules' pattern		audit rule skeleton for same syscall
# * syscall group			greatest common string this rule shares
# 					with other rules from the same group
# * architecture			architecture this rule is intended for
# * full form of new rule to add	expected full form of audit rule as to be
# 					added into audit.rules file
#
# Note: The 2-th up to 4-th arguments are used to determine how many existing
# audit rules will be inspected for resemblance with the new audit rule
# (5-th argument) the function is going to add. The rule's similarity check
# is performed to optimize audit.rules definition (merge syscalls of the same
# group into one rule) to avoid the "single-syscall-per-audit-rule" performance
# penalty.
#
# Example call:
#
#	See e.g. 'audit_rules_file_deletion_events.sh' remediation script
#
function fix_audit_syscall_rule {

# Load function arguments into local variables
local tool="$1"
local pattern="$2"
local group="$3"
local arch="$4"
local full_rule="$5"

# Check sanity of the input
if [ $# -ne "5" ]
then
	echo "Usage: fix_audit_syscall_rule 'tool' 'pattern' 'group' 'arch' 'full rule'"
	echo "Aborting."
	exit 1
fi

# 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  |
# ----------------------------------------------------------------------------