Guide to the Secure Configuration of Oracle Linux 7

with profile ANSSI-BP-028 (intermediary)
This profile contains configurations that align to ANSSI-BP-028 at the intermediary hardening level. ANSSI is the French National Information Security Agency, and stands for Agence nationale de la sécurité des systèmes d'information. ANSSI-BP-028 is a configuration recommendation for GNU/Linux systems. A copy of the ANSSI-BP-028 can be found at the ANSSI website: https://www.ssi.gouv.fr/administration/guide/recommandations-de-securite-relatives-a-un-systeme-gnulinux/
The SCAP Security Guide Project
https://www.open-scap.org/security-policies/scap-security-guide
This guide presents a catalog of security-relevant configuration settings for Oracle Linux 7. 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 TitleANSSI-BP-028 (intermediary)
Profile IDxccdf_org.ssgproject.content_profile_anssi_nt28_intermediary

CPE Platforms

  • cpe:/o:oracle:linux:7

Revision History

Current version: 0.1.68

  • draft (as of 2023-06-15)

Table of Contents

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

Checklist

Group   Guide to the Secure Configuration of Oracle Linux 7   Group contains 55 groups and 158 rules
Group   System Settings   Group contains 40 groups and 139 rules
[ref]   Contains rules that check correct system settings.
Group   Installing and Maintaining Software   Group contains 6 groups and 27 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 2 groups and 2 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 2 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 AIDE   Group contains 2 rules
[ref]   AIDE conducts integrity checks by comparing information about files with previously-gathered information. Ideally, the AIDE database is created immediately after initial system configuration, and then again after any software update. AIDE is highly configurable, with further configuration information located in /usr/share/doc/aide-VERSION.

Rule   Install AIDE   [ref]

The aide package can be installed with the following command: 
$ sudo yum install aide
Rationale:
The AIDE package must be installed if it is to be available for integrity checking.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_aide_installed
Identifiers and References

References:  BP28(R51), 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, CCI-002696, CCI-002699, CCI-001744, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, 1034, 1288, 1341, 1417, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, 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, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, 11.5.2, SRG-OS-000445-GPOS-00199, OL07-00-020029, SV-251701r880693_rule


Complexity:low
Disruption:low
Strategy:enable

package --add=aide



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

Complexity:low
Disruption:low
Strategy:enable
include install_aide

class install_aide {
  package { 'aide':
    ensure => 'installed',
  }
}

Complexity:low
Disruption:low
Strategy:enable
- name: Ensure aide is installed
  package:
    name: aide
    state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - DISA-STIG-OL07-00-020029
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_aide_installed

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

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

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

Rule   Build and Test AIDE Database   [ref]

Run the following command to generate a new database: 
$ sudo /usr/sbin/aide --init
By default, the database will be written to the file /var/lib/aide/aide.db.new.gz. Storing the database, the configuration file /etc/aide.conf, and the binary /usr/sbin/aide (or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity. The newly-generated database can be installed as follows: 
$ sudo cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz
To initiate a manual check, run the following command: 
$ sudo /usr/sbin/aide --check
If this check produces any unexpected output, investigate.
Rationale:
For AIDE to be effective, an initial database of "known-good" information about files must be captured and it should be able to be verified against the installed files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_aide_build_database
Identifiers and References

References:  BP28(R51), 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, 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, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, 11.5.2, SRG-OS-000445-GPOS-00199, OL07-00-020029, SV-251701r880693_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Ensure AIDE is installed
  package:
    name: '{{ item }}'
    state: present
  with_items:
  - aide
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - DISA-STIG-OL07-00-020029
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_build_database
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Build and Test AIDE Database
  command: /usr/sbin/aide --init
  changed_when: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - DISA-STIG-OL07-00-020029
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_build_database
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check whether the stock AIDE Database exists
  stat:
    path: /var/lib/aide/aide.db.new.gz
  register: aide_database_stat
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.3
  - DISA-STIG-OL07-00-020029
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_build_database
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Stage AIDE Database
  copy:
    src: /var/lib/aide/aide.db.new.gz
    dest: /var/lib/aide/aide.db.gz
    backup: true
    remote_src: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (aide_database_stat.stat.exists is defined and aide_database_stat.stat.exists)
  tags:
  - CJIS-5.10.1.3
  - DISA-STIG-OL07-00-020029
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-11.5
  - PCI-DSSv4-11.5.2
  - aide_build_database
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


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

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

/usr/sbin/aide --init
/bin/cp -p /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Disk Partitioning   Group contains 9 rules
[ref]   To ensure separation and protection of data, there are top-level system directories which should be placed on their own physical partition or logical volume. The installer's default partitioning scheme creates separate logical volumes for /, /boot, and swap.
  • If starting with any of the default layouts, check the box to \"Review and modify partitioning.\" This allows for the easy creation of additional logical volumes inside the volume group already created, though it may require making /'s logical volume smaller to create space. In general, using logical volumes is preferable to using partitions because they can be more easily adjusted later.
  • If creating a custom layout, create the partitions mentioned in the previous paragraph (which the installer will require anyway), as well as separate ones described in the following sections.
If a system has already been installed, and the default partitioning scheme was used, it is possible but nontrivial to modify it to create separate logical volumes for the directories listed above. The Logical Volume Manager (LVM) makes this possible. See the LVM HOWTO at http://tldp.org/HOWTO/LVM-HOWTO/ for more detailed information on LVM.

Rule   Ensure /boot Located On Separate Partition   [ref]

It is recommended that the /boot directory resides on a separate partition. This makes it easier to apply restrictions e.g. through the noexec mount option. Eventually, the /boot partition can be configured not to be mounted automatically with the noauto mount option.
Rationale:
The /boot partition contains the kernel and bootloader files. Access to this partition should be restricted.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_boot
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /boot

Rule   Ensure /home Located On Separate Partition   [ref]

If user home directories will be stored locally, create a separate partition for /home at installation time (or migrate it later using LVM). If /home will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.
Rationale:
Ensuring that /home is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_home
Identifiers and References

References:  BP28(R12), 12, 15, 8, APO13.01, DSS05.02, CCI-000366, CCI-001208, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-021310, SV-221754r603803_rule


Complexity:low
Disruption:high
Strategy:enable

part /home

Rule   Ensure /opt Located On Separate Partition   [ref]

It is recommended that the /opt directory resides on a separate partition.
Rationale:
The /opt partition contains additional software, usually installed outside the packaging system. Putting this directory on a separate partition makes it easier to apply restrictions e.g. through the nosuid mount option.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_opt
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /opt

Rule   Ensure /srv Located On Separate Partition   [ref]

If a file server (FTP, TFTP...) is hosted locally, create a separate partition for /srv at installation time (or migrate it later using LVM). If /srv will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.
Rationale:
Srv deserves files for local network file server such as FTP. Ensuring that /srv is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_srv
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /srv

Rule   Ensure /tmp Located On Separate Partition   [ref]

The /tmp directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale:
The /tmp partition is used as temporary storage by many programs. Placing /tmp in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_tmp
Identifiers and References

References:  BP28(R12), 12, 15, 8, APO13.01, DSS05.02, CCI-000366, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-021340, SV-221757r603260_rule


Complexity:low
Disruption:high
Strategy:enable

part /tmp

Rule   Ensure /usr Located On Separate Partition   [ref]

It is recommended that the /usr directory resides on a separate partition.
Rationale:
The /usr partition contains system software, utilities and files. Putting it on a separate partition allows limiting its size and applying restrictions through mount options.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_usr
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /usr

Rule   Ensure /var Located On Separate Partition   [ref]

The /var directory is used by daemons and other system services to store frequently-changing data. Ensure that /var has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale:
Ensuring that /var is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the /var directory to contain world-writable directories installed by other software packages.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_var
Identifiers and References

References:  BP28(R12), 12, 15, 8, APO13.01, DSS05.02, CCI-000366, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-021320, SV-221755r603260_rule


Complexity:low
Disruption:high
Strategy:enable

part /var

Rule   Ensure /var/log Located On Separate Partition   [ref]

System logs are stored in the /var/log directory. Ensure that /var/log has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale:
Placing /var/log in its own partition enables better separation between log files and other files in /var/.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_var_log
Identifiers and References

References:  BP28(R12), BP28(R47), 1, 12, 14, 15, 16, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, DSS05.02, DSS05.04, DSS05.07, MEA02.01, CCI-000366, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.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, CIP-007-3 R6.5, CM-6(a), AU-4, SC-5(2), PR.PT-1, PR.PT-4, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:high
Strategy:enable

part /var/log

Rule   Ensure /var/tmp Located On Separate Partition   [ref]

The /var/tmp directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale:
The /var/tmp partition is used as temporary storage by many programs. Placing /var/tmp in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_partition_for_var_tmp
Identifiers and References

References:  BP28(R12), SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:high
Strategy:enable

part /var/tmp
Group   Sudo   Group contains 11 rules
[ref]   Sudo, which stands for "su 'do'", provides the ability to delegate authority to certain users, groups of users, or system administrators. When configured for system users and/or groups, Sudo can allow a user or group to execute privileged commands that normally only root is allowed to execute.

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

Rule   Install sudo Package   [ref]

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

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


Complexity:low
Disruption:low
Strategy:enable

package --add=sudo



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

Complexity:low
Disruption:low
Strategy:enable
include install_sudo

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

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

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

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

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

Rule   Ensure sudo Runs In A Minimal Environment - sudo env_reset   [ref]

The sudo env_reset tag, when specified, will run the command in a minimal environment, containing the TERM, PATH, HOME, MAIL, SHELL, LOGNAME, USER and SUDO_* variables. This should be enabled by making sure that the env_reset tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
Forcing sudo to reset the environment ensures that environment variables are not passed on to the command accidentaly, preventing leak of potentially sensitive information.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_env_reset
Identifiers and References

References:  BP28(R58)


Complexity:low
Disruption:low
Strategy:restrict
- name: Ensure env_reset is enabled in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults.*\benv_reset\b.*$
    line: Defaults env_reset
    validate: /usr/sbin/visudo -cf %s
  tags:
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_env_reset

Complexity:low
Disruption:low
Strategy:restrict

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

Rule   Ensure sudo Ignores Commands In Current Dir - sudo ignore_dot   [ref]

The sudo ignore_dot tag, when specified, will ignore the current directory in the PATH environment variable. This should be enabled by making sure that the ignore_dot tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
Ignoring the commands in the user's current directory prevents an attacker from executing commands downloaded locally.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_ignore_dot
Identifiers and References

References:  BP28(R58)


Complexity:low
Disruption:low
Strategy:restrict
- name: Ensure ignore_dot is enabled in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults.*\bignore_dot\b.*$
    line: Defaults ignore_dot
    validate: /usr/sbin/visudo -cf %s
  tags:
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_ignore_dot

Complexity:low
Disruption:low
Strategy:restrict

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

Rule   Ensure Privileged Escalated Commands Cannot Execute Other Commands - sudo NOEXEC   [ref]

The sudo NOEXEC tag, when specified, prevents user executed commands from executing other commands, like a shell for example. This should be enabled by making sure that the NOEXEC tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
Restricting the capability of sudo allowed commands to execute sub-commands prevents users from running programs with privileges they wouldn't have otherwise.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_noexec
Identifiers and References

References:  BP28(R58)


Complexity:low
Disruption:low
Strategy:restrict
- name: Ensure noexec is enabled in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults.*\bnoexec\b.*$
    line: Defaults noexec
    validate: /usr/sbin/visudo -cf %s
  tags:
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_noexec

Complexity:low
Disruption:low
Strategy:restrict

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

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

The sudo requiretty tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by making sure that the requiretty tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
Restricting the use cases in which a user is allowed to execute sudo commands reduces the attack surface.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_requiretty
Identifiers and References

References:  BP28(R58)


Complexity:low
Disruption:low
Strategy:restrict
- name: Ensure requiretty is enabled in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults.*\brequiretty\b.*$
    line: Defaults requiretty
    validate: /usr/sbin/visudo -cf %s
  tags:
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_requiretty

Complexity:low
Disruption:low
Strategy:restrict

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

Rule   Ensure sudo umask is appropriate - sudo umask   [ref]

The sudo umask tag, when specified, will be added the to the user's umask in the command environment. The umask should be configured by making sure that the umask=0077 tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.
Rationale:
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudo_add_umask
Identifiers and References

References:  BP28(R58)


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_sudo_umask # promote to variable
  set_fact:
    var_sudo_umask: !!str 0077
  tags:
    - always

- name: Ensure umask is enabled with the appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    regexp: ^[\s]*Defaults\s(.*)\bumask=[-]?.+\b(.*)$
    line: Defaults \1umask={{ var_sudo_umask }}\2
    validate: /usr/sbin/visudo -cf %s
    backrefs: true
  register: edit_sudoers_umask_option
  tags:
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_umask

- name: Enable umask option with appropriate value in /etc/sudoers
  lineinfile:
    path: /etc/sudoers
    line: Defaults umask={{ var_sudo_umask }}
    validate: /usr/sbin/visudo -cf %s
  when: edit_sudoers_umask_option is defined and not edit_sudoers_umask_option.changed
  tags:
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_add_umask

Complexity:low
Disruption:low
Strategy:restrict


var_sudo_umask='0077'


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

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

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

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


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

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

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

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

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

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

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

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

References:  BP28(R5), BP28(R59), 1, 12, 15, 16, 5, DSS05.04, DSS05.10, DSS06.03, DSS06.10, CCI-002038, 4.3.3.5.1, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-11, CM-6(a), PR.AC-1, PR.AC-7, SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158, OL07-00-010350, SV-228569r853731_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Find /etc/sudoers.d/ files
  find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - DISA-STIG-OL07-00-010350
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_no_authenticate

- name: Remove lines containing !authenticate from sudoers files
  replace:
    regexp: (^(?!#).*[\s]+\!authenticate.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - DISA-STIG-OL07-00-010350
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_no_authenticate

Complexity:low
Disruption:low
Strategy:restrict

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

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

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

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

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

References:  BP28(R5), BP28(R59), 1, 12, 15, 16, 5, DSS05.04, DSS05.10, DSS06.03, DSS06.10, CCI-002038, 4.3.3.5.1, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-11, CM-6(a), PR.AC-1, PR.AC-7, SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158, OL07-00-010340, SV-221692r860860_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Find /etc/sudoers.d/ files
  find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - DISA-STIG-OL07-00-010340
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_nopasswd

- name: Remove lines containing NOPASSWD from sudoers files
  replace:
    regexp: (^(?!#).*[\s]+NOPASSWD[\s]*\:.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - DISA-STIG-OL07-00-010340
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_nopasswd

Complexity:low
Disruption:low
Strategy:restrict

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

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

Rule   Explicit arguments in sudo specifications   [ref]

All commands in the sudoers file must strictly specify the arguments allowed to be used for a given user. If the command is supposed to be executed only without arguments, pass "" as an argument in the corresponding user specification.
Warning:  This rule doesn't come with a remediation, as absence of arguments in the user spec doesn't mean that the command is intended to be executed with no arguments.
Warning:  The rule can produce false findings when an argument contains a comma - sudoers syntax allows comma escaping using backslash, but the check doesn't support that. For example, root ALL=(ALL) echo 1\,2 allows root to execute echo 1,2, but the check would interpret it as two commands echo 1\ and 2.
Rationale:
Any argument can modify quite significantly the behavior of a program, whether regarding the realized operation (read, write, delete, etc.) or accessed resources (path in a file system tree). To avoid any possibility of misuse of a command by a user, the ambiguities must be removed at the level of its specification. For example, on some systems, the kernel messages are only accessible by root. If a user nevertheless must have the privileges to read them, the argument of the dmesg command has to be restricted in order to prevent the user from flushing the buffer through the -c option: 
user ALL = dmesg ""
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudoers_explicit_command_args
Identifiers and References

References:  BP28(R63)

Rule   Don't define allowed commands in sudoers by means of exclusion   [ref]

Policies applied by sudo through the sudoers file should not involve negation. Each user specification in the sudoers file contains a comma-delimited list of command specifications. The definition can make use glob patterns, as well as of negations. Indirect definition of those commands by means of exclusion of a set of commands is trivial to bypass, so it is not allowed to use such constructs.
Warning:  This rule doesn't come with a remediation, as negations indicate design issues with the sudoers user specifications design. Just removing negations doesn't increase the security - you typically have to rethink the definition of allowed commands to fix the issue.
Rationale:
Specifying access right using negation is inefficient and can be easily circumvented. For example, it is expected that a specification like 
# To avoid absolutely , this rule can be easily circumvented!
user ALL = ALL ,!/ bin/sh
prevents the execution of the shell but that’s not the case: just copy the binary /bin/sh to a different name to make it executable again through the rule keyword ALL.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sudoers_no_command_negation
Identifiers and References

References:  BP28(R61)

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.

Oracle Linux 7 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:  BP28(R15), 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 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), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 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, 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, 6.3.3, SRG-OS-000366-GPOS-00153, OL07-00-020050, SV-221710r877463_rule


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.10.4.1
  - DISA-STIG-OL07-00-020050
  - 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
  - PCI-DSSv4-6.3.3
  - configure_strategy
  - ensure_gpgcheck_globally_activated
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed

- name: Ensure GPG check is globally activated
  ini_file:
    dest: /etc/yum.conf
    section: main
    option: gpgcheck
    value: 1
    no_extra_spaces: true
    create: false
  when: '"yum" in ansible_facts.packages'
  tags:
  - CJIS-5.10.4.1
  - DISA-STIG-OL07-00-020050
  - 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
  - PCI-DSSv4-6.3.3
  - configure_strategy
  - ensure_gpgcheck_globally_activated
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed


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

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

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:  BP28(R15), 11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 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), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-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, OL07-00-020060, SV-221711r877463_rule


Complexity:low
Disruption:medium
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-020060
  - 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)
  block:

  - name: Check stats of yum
    stat:
      path: /etc/yum.conf
    register: pkg

  - name: Check if config file of yum is a symlink
    ansible.builtin.set_fact:
      pkg_config_file_symlink: '{{ pkg.stat.lnk_target if pkg.stat.lnk_target is match("^/.*")
        else "/etc/yum.conf" | dirname ~ "/" ~ pkg.stat.lnk_target }}'
    when: pkg.stat.lnk_target is defined

  - name: Ensure GPG check Enabled for Local Packages (yum)
    ini_file:
      dest: '{{ pkg_config_file_symlink |  default("/etc/yum.conf") }}'
      section: main
      option: localpkg_gpgcheck
      value: 1
      no_extra_spaces: true
      create: true
  when: '"yum" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-020060
  - 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


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

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

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:  BP28(R15), 11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 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), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 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, 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, 6.3.3, SRG-OS-000366-GPOS-00153


Complexity:low
Disruption:medium
Strategy:enable
- name: Grep for yum repo section names
  shell: |
    set -o pipefail
    grep -HEr '^\[.+\]' -r /etc/yum.repos.d/
  register: repo_grep_results
  failed_when: repo_grep_results.rc not in [0, 1]
  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
  - PCI-DSSv4-6.3.3
  - 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
  - PCI-DSSv4-6.3.3
  - enable_strategy
  - ensure_gpgcheck_never_disabled
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed



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

Rule   Ensure Oracle Linux GPG Key Installed   [ref]

To ensure the system can cryptographically verify base software packages come from Oracle (and to connect to the Unbreakable Linux Network to receive them), the Oracle GPG key must properly be installed. To install the Oracle GPG key, run: 
$ sudo uln_register
If the system is not connected to the Internet, then install the Oracle GPG key from trusted media such as the Oracle 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-oracle
Alternatively, the key may be pre-loaded during the Oracle installation. In such cases, the key can be installed by running the following command: 
sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
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 Oracle GPG key is necessary to cryptographically verify packages are from Oracle.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_ensure_oracle_gpgkey_installed
Identifiers and References

References:  11, 2, 3, 9, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, CCI-001749, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, 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, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, Req-6.2, OL07-00-010019, 1.2.2, SV-256975r902762_rule


# OL fingerprints below retrieved from: https://linux.oracle.com/security/gpg/#gpg
readonly OL_RELEASE_FINGERPRINT="42144123FECFC55B9086313D72F97B74EC551F03"
readonly OL_AUXILIARY_FINGERPRINT=""

FINGERPRINTS_REGEX="${OL_RELEASE_FINGERPRINT}"

if [[ -n "$OL_AUXILIARY_FINGERPRINT" ]]; then
    FINGERPRINTS_REGEX+="|${OL_AUXILIARY_FINGERPRINT}"
fi

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

RPM_GPG_DIR_PERMS=$(stat -c %a "$(dirname "$OL_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 --with-fingerprint --with-colons "$OL_RELEASE_KEY" | grep "^fpr" | cut -d ":" -f 10)
  

  GPG_RESULT=$?
  # No CRC error, safe to proceed
  if [ "${GPG_RESULT}" -eq "0" ]
  then
    # Filter just hexadecimal fingerprints from gpg's output from
    # processing of a key file
    echo "${GPG_OUT[*]}" | grep -vE "$FINGERPRINTS_REGEX" || {
      # If $ OL_RELEASE_KEY file doesn't contain any keys with unknown fingerprint, import it
      rpm --import "${OL_RELEASE_KEY}"
    }
  fi
fi

Rule   Ensure Software Patches Installed   [ref]

If the system is joined to the ULN or a yum server, run the following command to install updates: 
$ sudo yum update
If the system is not configured to use one of these sources, updates (in the form of RPM packages) can be manually downloaded from the ULN and installed using rpm.

NOTE: U.S. Defense systems are required to be patched within 30 days or sooner as local policy dictates.
Warning:  The OVAL feed of Oracle Linux 7 is not a XML file, which may not be understood by all scanners.
Rationale:
Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_security_patches_up_to_date
Identifiers and References

References:  BP28(R08), 18, 20, 4, 5.10.4.1, APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02, CCI-000366, CCI-001227, 4.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9, A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3, SI-2(5), SI-2(c), CM-6(a), ID.RA-1, PR.IP-12, FMT_MOF_EXT.1, Req-6.2, 6.3.3, SRG-OS-000480-GPOS-00227, OL07-00-020260, SV-221720r603260_rule


Complexity:low
Disruption:high
Reboot:true
Strategy:patch
- name: Security patches are up to date
  package:
    name: '*'
    state: latest
  tags:
  - CJIS-5.10.4.1
  - DISA-STIG-OL07-00-020260
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-2(5)
  - NIST-800-53-SI-2(c)
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3.3
  - high_disruption
  - low_complexity
  - medium_severity
  - patch_strategy
  - reboot_required
  - security_patches_up_to_date
  - skip_ansible_lint

Complexity:low
Disruption:high
Reboot:true
Strategy:patch


yum -y update
Group   Account and Access Control   Group contains 10 groups and 20 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 Oracle Linux 7.
Group   Protect Accounts by Configuring PAM   Group contains 4 groups and 12 rules
[ref]   PAM, or Pluggable Authentication Modules, is a system which implements modular authentication for Linux programs. PAM provides a flexible and configurable architecture for authentication, and it should be configured to minimize exposure to unnecessary risk. This section contains guidance on how to accomplish that.

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

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

One very important file in /etc/pam.d is /etc/pam.d/system-auth. This file, which is included by many other PAM configuration files, defines 'default' system authentication measures. Modifying this file is a good way to make far-reaching authentication changes, for instance when implementing a centralized authentication service.
Warning:  Be careful when making changes to PAM's configuration files. The syntax for these files is complex, and modifications can have unexpected consequences. The default configurations shipped with applications should be sufficient for most users.
Warning:  Running authconfig or system-config-authentication will re-write the PAM configuration files, destroying any manually made changes and replacing them with a series of system defaults. One reference to the configuration file syntax can be found at https://fossies.org/linux/Linux-PAM-docs/doc/sag/Linux-PAM_SAG.pdf.
Group   Set Lockouts for Failed Password Attempts   Group contains 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   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.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report.
Warning:  Newer versions of authselect contain an authselect feature to easily and properly enable pam_pwhistory.so module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files.
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:  BP28(R18), 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, CCI-000200, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(e), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.5, 8.3.7, SRG-OS-000077-GPOS-00045


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
  - PCI-DSSv4-8.3.7
  - 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 2
  tags:
    - always

- name: Limit Password Reuse - Check if system relies on authselect tool
  ansible.builtin.stat:
    path: /usr/bin/authselect
  register: result_authselect_present
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Limit Password Reuse - Collect the available authselect features
  ansible.builtin.command:
    cmd: authselect list-features minimal
  register: result_authselect_available_features
  changed_when: false
  when:
  - '"pam" in ansible_facts.packages'
  - result_authselect_present.stat.exists
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Limit Password Reuse - Enable pam_pwhistory.so using authselect feature
  block:

  - name: Limit Password Reuse - Check integrity of authselect current profile
    ansible.builtin.command:
      cmd: authselect check
    register: result_authselect_check_cmd
    changed_when: false
    failed_when: false

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

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

  - name: Limit Password Reuse - Ensure "with-pwhistory" feature is enabled using
      authselect tool
    ansible.builtin.command:
      cmd: authselect enable-feature with-pwhistory
    register: result_authselect_enable_feature_cmd
    when:
    - result_authselect_check_cmd is success
    - result_authselect_features.stdout is not search("with-pwhistory")

  - name: Limit Password Reuse - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_enable_feature_cmd is not skipped
    - result_authselect_enable_feature_cmd is success
  when:
  - '"pam" in ansible_facts.packages'
  - result_authselect_present.stat.exists
  - result_authselect_available_features.stdout is search("with-pwhistory")
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Limit Password Reuse - Enable pam_pwhistory.so in appropriate PAM files
  block:

  - name: Limit Password Reuse - Define the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Limit Password Reuse - Check if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Limit Password Reuse - Ensure authselect custom profile is used if authselect
      is present
    block:

    - name: Limit Password Reuse - Check integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

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

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

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

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

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

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

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

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

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

    - name: Limit Password Reuse - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

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

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

  - name: Limit Password Reuse - Include or update the PAM module line in {{ pam_file_path
      }}
    block:

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

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

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

    - name: Limit Password Reuse - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present is defined
      - result_authselect_present.stat.exists
      - |-
        (result_pam_module_add is defined and result_pam_module_add.changed)
         or (result_pam_module_edit is defined and result_pam_module_edit.changed)
    when:
    - result_pam_line_present.found is defined
    - result_pam_line_present.found == 0
  when:
  - '"pam" in ansible_facts.packages'
  - |
    (result_authselect_available_features.stdout is defined and result_authselect_available_features.stdout is not search("with-pwhistory")) or result_authselect_available_features is not defined
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Limit Password Reuse - Check the presence of /etc/security/pwhistory.conf
    file
  ansible.builtin.stat:
    path: /etc/security/pwhistory.conf
  register: result_pwhistory_conf_check
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Limit Password Reuse - pam_pwhistory.so parameters are configured in /etc/security/pwhistory.conf
    file
  block:

  - name: Limit Password Reuse - Ensure the pam_pwhistory.so remember parameter in
      /etc/security/pwhistory.conf
    ansible.builtin.lineinfile:
      path: /etc/security/pwhistory.conf
      regexp: ^\s*remember\s*=
      line: remember = {{ var_password_pam_unix_remember }}
      state: present

  - name: Limit Password Reuse - Ensure the pam_pwhistory.so remember parameter is
      removed from PAM files
    block:

    - name: Limit Password Reuse - Check if /etc/pam.d/system-auth file is present
      ansible.builtin.stat:
        path: /etc/pam.d/system-auth
      register: result_pam_file_present

    - name: Limit Password Reuse - Check the proper remediation for the system
      block:

      - name: Limit Password Reuse - Define the PAM file to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Limit Password Reuse - Check if system relies on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Limit Password Reuse - Ensure authselect custom profile is used if authselect
          is present
        block:

        - name: Limit Password Reuse - Check integrity of authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          failed_when: false

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

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

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

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

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

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

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

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

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

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

        - name: Limit Password Reuse - Ensure authselect changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

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

      - name: Limit Password Reuse - Ensure the "remember" option from "pam_pwhistory.so"
          is not present in {{ pam_file_path }}
        ansible.builtin.replace:
          dest: '{{ pam_file_path }}'
          regexp: (.*password.*pam_pwhistory.so.*)\bremember\b=?[0-9a-zA-Z]*(.*)
          replace: \1\2
        register: result_pam_option_removal

      - name: Limit Password Reuse - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - result_pam_option_removal is changed
      when:
      - result_pam_file_present.stat.exists
  when:
  - '"pam" in ansible_facts.packages'
  - result_pwhistory_conf_check.stat.exists
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Limit Password Reuse - pam_pwhistory.so parameters are configured in PAM files
  block:

  - name: Limit Password Reuse - Define the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Limit Password Reuse - Check if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Limit Password Reuse - Ensure authselect custom profile is used if authselect
      is present
    block:

    - name: Limit Password Reuse - Check integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

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

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

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

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

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

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

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

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

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

    - name: Limit Password Reuse - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

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

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

  - name: Limit Password Reuse - Include or update the PAM module line in {{ pam_file_path
      }}
    block:

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

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

    - name: Limit Password Reuse - Ensure the required PAM module line is included
        in {{ pam_file_path }}
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        line: password    requisite    pam_pwhistory.so
      register: result_pam_module_add
      when:
      - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
        > 1

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

  - name: Limit Password Reuse - Check if the required PAM module option is present
      in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      regexp: ^\s*password\s+requisite\s+pam_pwhistory.so\s*.*\sremember\b
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_module_remember_option_present

  - name: Limit Password Reuse - Ensure the "remember" PAM option for "pam_pwhistory.so"
      is included in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so.*)
      line: \1 remember={{ var_password_pam_unix_remember }}
      state: present
    register: result_pam_remember_add
    when:
    - result_pam_module_remember_option_present.found == 0

  - name: Limit Password Reuse - Ensure the required value for "remember" PAM option
      from "pam_pwhistory.so" in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so\s+.*)(remember)=[0-9a-zA-Z]+\s*(.*)
      line: \1\2={{ var_password_pam_unix_remember }} \3
    register: result_pam_remember_edit
    when:
    - result_pam_module_remember_option_present.found > 0

  - name: Limit Password Reuse - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - (result_pam_remember_add is defined and result_pam_remember_add.changed) or
      (result_pam_remember_edit is defined and result_pam_remember_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - not result_pwhistory_conf_check.stat.exists
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_unix_remember
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed


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

var_password_pam_unix_remember='2'


if [ -f /usr/bin/authselect ]; then
    if authselect list-features minimal | grep -q with-pwhistory; then
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi
        authselect enable-feature with-pwhistory

        authselect apply-changes -b
    else
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

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

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

PWHISTORY_CONF="/etc/security/pwhistory.conf"
if [ -f $PWHISTORY_CONF ]; then
    regex="^\s*remember\s*="
    line="remember = $var_password_pam_unix_remember"
    if ! grep -q $regex $PWHISTORY_CONF; then
        echo $line >> $PWHISTORY_CONF
    else
        sed -i --follow-symlinks 's|^\s*\(remember\s*=\s*\)\(\S\+\)|\1'"$var_password_pam_unix_remember"'|g' $PWHISTORY_CONF
    fi
    if [ -e "/etc/pam.d/system-auth" ] ; then
        PAM_FILE_PATH="/etc/pam.d/system-auth"
        if [ -f /usr/bin/authselect ]; then
            
            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

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

            authselect apply-changes -b
        fi
        
    if grep -qP '^\s*password\s.*\bpam_pwhistory.so\s.*\bremember\b' "$PAM_FILE_PATH"; then
        sed -i -E --follow-symlinks 's/(.*password.*pam_pwhistory.so.*)\bremember\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
    fi
        if [ -f /usr/bin/authselect ]; then
            
            authselect apply-changes -b
        fi
    else
        echo "/etc/pam.d/system-auth was not found" >&2
    fi
else
    PAM_FILE_PATH="/etc/pam.d/system-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

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

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwhistory.so\s*.*' "$PAM_FILE_PATH"; then
        # Line matching group + control + module was not found. Check group + module.
        if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
            # The control is updated only if one single line matches.
            sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1'"requisite"' \2/' "$PAM_FILE_PATH"
        else
            echo 'password    '"requisite"'    pam_pwhistory.so' >> "$PAM_FILE_PATH"
        fi
    fi
    # Check the option
    if ! grep -qP '^\s*password\s+'"requisite"'\s+pam_pwhistory.so\s*.*\sremember\b' "$PAM_FILE_PATH"; then
        sed -i -E --follow-symlinks '/\s*password\s+'"requisite"'\s+pam_pwhistory.so.*/ s/$/ remember='"$var_password_pam_unix_remember"'/' "$PAM_FILE_PATH"
    else
        sed -i -E --follow-symlinks 's/(\s*password\s+'"requisite"'\s+pam_pwhistory.so\s+.*)('"remember"'=)[[:alnum:]]+\s*(.*)/\1\2'"$var_password_pam_unix_remember"' \3/' "$PAM_FILE_PATH"
    fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
fi

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

Rule   Lock Accounts After Failed Password Attempts   [ref]

This rule configures the system to lock out accounts after a number of incorrect login attempts using pam_faillock.so. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid errors when manually editing these files, it is recommended to use the appropriate tools, such as authselect or authconfig, depending on the OS version.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
Rationale:
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also 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
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, Req-8.1.6, 8.3.4, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, OL07-00-010320, SV-221690r880681_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Lock Accounts After Failed Password Attempts - Check if system relies on authselect
    tool
  ansible.builtin.stat:
    path: /usr/bin/authselect
  register: result_authselect_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Lock Accounts After Failed Password Attempts - Remediation where authselect
    tool is present
  block:

  - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
      current profile
    ansible.builtin.command:
      cmd: authselect check
    register: result_authselect_check_cmd
    changed_when: false
    failed_when: false

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

  - name: Lock Accounts After Failed Password Attempts - Get authselect current features
    ansible.builtin.shell:
      cmd: authselect current | tail -n+3 | awk '{ print $2 }'
    register: result_authselect_features
    changed_when: false
    when:
    - result_authselect_check_cmd is success

  - name: Lock Accounts After Failed Password Attempts - Ensure "with-faillock" feature
      is enabled using authselect tool
    ansible.builtin.command:
      cmd: authselect enable-feature with-faillock
    register: result_authselect_enable_feature_cmd
    when:
    - result_authselect_check_cmd is success
    - result_authselect_features.stdout is not search("with-faillock")

  - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
      are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_enable_feature_cmd is not skipped
    - result_authselect_enable_feature_cmd is success
  when:
  - '"pam" in ansible_facts.packages'
  - result_authselect_present.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Lock Accounts After Failed Password Attempts - Remediation where authselect
    tool is not present
  block:

  - name: Lock Accounts After Failed Password Attempts - Check if pam_faillock.so
      is already enabled
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail)
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_is_enabled

  - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so preauth
      editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so preauth
      insertbefore: ^auth.*sufficient.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so authfail
      editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so authfail
      insertbefore: ^auth.*required.*pam_deny\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so account
      section editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: account     required      pam_faillock.so
      insertbefore: ^account.*required.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_authselect_present.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - 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: Lock Accounts After Failed Password Attempts - Check the presence of /etc/security/faillock.conf
    file
  ansible.builtin.stat:
    path: /etc/security/faillock.conf
  register: result_faillock_conf_check
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
    deny parameter in /etc/security/faillock.conf
  ansible.builtin.lineinfile:
    path: /etc/security/faillock.conf
    regexp: ^\s*deny\s*=
    line: deny = {{ var_accounts_passwords_pam_faillock_deny }}
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
    deny parameter not in PAM files
  block:

  - name: Lock Accounts After Failed Password Attempts - Check if /etc/pam.d/system-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/system-auth
    register: result_pam_file_present

  - name: Lock Accounts After Failed Password Attempts - Check the proper remediation
      for the system
    block:

    - name: Lock Accounts After Failed Password Attempts - Define the PAM file to
        be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/system-auth

    - name: Lock Accounts After Failed Password Attempts - Check if system relies
        on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Lock Accounts After Failed Password Attempts - Ensure authselect custom
        profile is used if authselect is present
      block:

      - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Lock Accounts After Failed Password Attempts - Get authselect current
          profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Lock Accounts After Failed Password Attempts - Define the current authselect
          profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

      - name: Lock Accounts After Failed Password Attempts - Define the new authselect
          custom profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: custom/hardening
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is not match("custom/")

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

      - name: Lock Accounts After Failed Password Attempts - Check if any custom profile
          with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Lock Accounts After Failed Password Attempts - Create an authselect
          custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Lock Accounts After Failed Password Attempts - Ensure the authselect
          custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Lock Accounts After Failed Password Attempts - Restore the authselect
          features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Lock Accounts After Failed Password Attempts - Change the PAM file to
          be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Lock Accounts After Failed Password Attempts - Ensure the "deny" option
        from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\bdeny\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
        are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists

  - name: Lock Accounts After Failed Password Attempts - Check if /etc/pam.d/password-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/password-auth
    register: result_pam_file_present

  - name: Lock Accounts After Failed Password Attempts - Check the proper remediation
      for the system
    block:

    - name: Lock Accounts After Failed Password Attempts - Define the PAM file to
        be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/password-auth

    - name: Lock Accounts After Failed Password Attempts - Check if system relies
        on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Lock Accounts After Failed Password Attempts - Ensure authselect custom
        profile is used if authselect is present
      block:

      - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Lock Accounts After Failed Password Attempts - Get authselect current
          profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Lock Accounts After Failed Password Attempts - Define the current authselect
          profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

      - name: Lock Accounts After Failed Password Attempts - Define the new authselect
          custom profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: custom/hardening
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is not match("custom/")

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

      - name: Lock Accounts After Failed Password Attempts - Check if any custom profile
          with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Lock Accounts After Failed Password Attempts - Create an authselect
          custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Lock Accounts After Failed Password Attempts - Ensure the authselect
          custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Lock Accounts After Failed Password Attempts - Restore the authselect
          features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Lock Accounts After Failed Password Attempts - Change the PAM file to
          be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Lock Accounts After Failed Password Attempts - Ensure the "deny" option
        from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\bdeny\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
        are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
    deny parameter in PAM files
  block:

  - name: Lock Accounts After Failed Password Attempts - Check if pam_faillock.so
      deny parameter is already enabled in pam files
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail).*deny
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_deny_parameter_is_present

  - name: Lock Accounts After Failed Password Attempts - Ensure the inclusion of pam_faillock.so
      preauth deny parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
      line: \1required\3 deny={{ var_accounts_passwords_pam_faillock_deny }}
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_deny_parameter_is_present.found == 0

  - name: Lock Accounts After Failed Password Attempts - Ensure the inclusion of pam_faillock.so
      authfail deny parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
      line: \1required\3 deny={{ var_accounts_passwords_pam_faillock_deny }}
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_deny_parameter_is_present.found == 0

  - name: Lock Accounts After Failed Password Attempts - Ensure the desired value
      for pam_faillock.so preauth deny parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)(deny)=[0-9]+(.*)
      line: \1required\3\4={{ var_accounts_passwords_pam_faillock_deny }}\5
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_deny_parameter_is_present.found > 0

  - name: Lock Accounts After Failed Password Attempts - Ensure the desired value
      for pam_faillock.so authfail deny parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)(deny)=[0-9]+(.*)
      line: \1required\3\4={{ var_accounts_passwords_pam_faillock_deny }}\5
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_deny_parameter_is_present.found > 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_faillock_conf_check.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.6
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_deny
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


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

var_accounts_passwords_pam_faillock_deny='3'


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

authselect apply-changes -b
else
    
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
for pam_file in "${AUTH_FILES[@]}"
do
    if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
        sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
        sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
    fi
    sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
done

fi

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

FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ]; then
    regex="^\s*deny\s*="
    line="deny = $var_accounts_passwords_pam_faillock_deny"
    if ! grep -q $regex $FAILLOCK_CONF; then
        echo $line >> $FAILLOCK_CONF
    else
        sed -i --follow-symlinks 's|^\s*\(deny\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_deny"'|g' $FAILLOCK_CONF
    fi
    for pam_file in "${AUTH_FILES[@]}"
    do
        if [ -e "$pam_file" ] ; then
            PAM_FILE_PATH="$pam_file"
            if [ -f /usr/bin/authselect ]; then
                
                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

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

                authselect apply-changes -b
            fi
            
        if grep -qP '^\s*auth\s.*\bpam_faillock.so\s.*\bdeny\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks 's/(.*auth.*pam_faillock.so.*)\bdeny\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then
                
                authselect apply-changes -b
            fi
        else
            echo "$pam_file was not found" >&2
        fi
    done
else
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth.*pam_faillock\.so (preauth|authfail).*deny' "$pam_file"; then
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*silent.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
        else
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*silent.*\)\('"deny"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"deny"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
        fi
    done
fi

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

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

This rule configures the system to lock out the root account after a number of incorrect login attempts using pam_faillock.so. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid errors when manually editing these files, it is recommended to use the appropriate tools, such as authselect or authconfig, depending on the OS version.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
Rationale:
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also 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:  BP28(R18), 1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, CCI-002238, CCI-000044, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, 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, OL07-00-010330, SV-221691r880684_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Check if system
    relies on authselect tool
  ansible.builtin.stat:
    path: /usr/bin/authselect
  register: result_authselect_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Remediation where
    authselect tool is present
  block:

  - name: Configure the root Account for Failed Password Attempts - Check integrity
      of authselect current profile
    ansible.builtin.command:
      cmd: authselect check
    register: result_authselect_check_cmd
    changed_when: false
    failed_when: false

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

  - name: Configure the root Account for Failed Password Attempts - Get authselect
      current features
    ansible.builtin.shell:
      cmd: authselect current | tail -n+3 | awk '{ print $2 }'
    register: result_authselect_features
    changed_when: false
    when:
    - result_authselect_check_cmd is success

  - name: Configure the root Account for Failed Password Attempts - Ensure "with-faillock"
      feature is enabled using authselect tool
    ansible.builtin.command:
      cmd: authselect enable-feature with-faillock
    register: result_authselect_enable_feature_cmd
    when:
    - result_authselect_check_cmd is success
    - result_authselect_features.stdout is not search("with-faillock")

  - name: Configure the root Account for Failed Password Attempts - Ensure authselect
      changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_enable_feature_cmd is not skipped
    - result_authselect_enable_feature_cmd is success
  when:
  - '"pam" in ansible_facts.packages'
  - result_authselect_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Remediation where
    authselect tool is not present
  block:

  - name: Configure the root Account for Failed Password Attempts - Check if pam_faillock.so
      is already enabled
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail)
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_is_enabled

  - name: Configure the root Account for Failed Password Attempts - Enable pam_faillock.so
      preauth editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so preauth
      insertbefore: ^auth.*sufficient.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Configure the root Account for Failed Password Attempts - Enable pam_faillock.so
      authfail editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so authfail
      insertbefore: ^auth.*required.*pam_deny\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Configure the root Account for Failed Password Attempts - Enable pam_faillock.so
      account section editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: account     required      pam_faillock.so
      insertbefore: ^account.*required.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_authselect_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Check the presence
    of /etc/security/faillock.conf file
  ansible.builtin.stat:
    path: /etc/security/faillock.conf
  register: result_faillock_conf_check
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Ensure the pam_faillock.so
    even_deny_root parameter in /etc/security/faillock.conf
  ansible.builtin.lineinfile:
    path: /etc/security/faillock.conf
    regexp: ^\s*even_deny_root
    line: even_deny_root
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Ensure the pam_faillock.so
    even_deny_root parameter not in PAM files
  block:

  - name: Configure the root Account for Failed Password Attempts - Check if /etc/pam.d/system-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/system-auth
    register: result_pam_file_present

  - name: Configure the root Account for Failed Password Attempts - Check the proper
      remediation for the system
    block:

    - name: Configure the root Account for Failed Password Attempts - Define the PAM
        file to be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/system-auth

    - name: Configure the root Account for Failed Password Attempts - Check if system
        relies on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Configure the root Account for Failed Password Attempts - Ensure authselect
        custom profile is used if authselect is present
      block:

      - name: Configure the root Account for Failed Password Attempts - Check integrity
          of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Configure the root Account for Failed Password Attempts - Get authselect
          current profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Configure the root Account for Failed Password Attempts - Define the
          current authselect profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

      - name: Configure the root Account for Failed Password Attempts - Define the
          new authselect custom profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: custom/hardening
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is not match("custom/")

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

      - name: Configure the root Account for Failed Password Attempts - Check if any
          custom profile with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Configure the root Account for Failed Password Attempts - Create an
          authselect custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Configure the root Account for Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Configure the root Account for Failed Password Attempts - Ensure the
          authselect custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Configure the root Account for Failed Password Attempts - Restore the
          authselect features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Configure the root Account for Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Configure the root Account for Failed Password Attempts - Change the
          PAM file to be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Configure the root Account for Failed Password Attempts - Ensure the "even_deny_root"
        option from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\beven_deny_root\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Configure the root Account for Failed Password Attempts - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists

  - name: Configure the root Account for Failed Password Attempts - Check if /etc/pam.d/password-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/password-auth
    register: result_pam_file_present

  - name: Configure the root Account for Failed Password Attempts - Check the proper
      remediation for the system
    block:

    - name: Configure the root Account for Failed Password Attempts - Define the PAM
        file to be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/password-auth

    - name: Configure the root Account for Failed Password Attempts - Check if system
        relies on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Configure the root Account for Failed Password Attempts - Ensure authselect
        custom profile is used if authselect is present
      block:

      - name: Configure the root Account for Failed Password Attempts - Check integrity
          of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Configure the root Account for Failed Password Attempts - Get authselect
          current profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Configure the root Account for Failed Password Attempts - Define the
          current authselect profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

      - name: Configure the root Account for Failed Password Attempts - Define the
          new authselect custom profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: custom/hardening
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is not match("custom/")

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

      - name: Configure the root Account for Failed Password Attempts - Check if any
          custom profile with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Configure the root Account for Failed Password Attempts - Create an
          authselect custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Configure the root Account for Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Configure the root Account for Failed Password Attempts - Ensure the
          authselect custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Configure the root Account for Failed Password Attempts - Restore the
          authselect features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Configure the root Account for Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Configure the root Account for Failed Password Attempts - Change the
          PAM file to be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Configure the root Account for Failed Password Attempts - Ensure the "even_deny_root"
        option from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\beven_deny_root\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Configure the root Account for Failed Password Attempts - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - DISA-STIG-OL07-00-010330
  - 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: Configure the root Account for Failed Password Attempts - Ensure the pam_faillock.so
    even_deny_root parameter in PAM files
  block:

  - name: Configure the root Account for Failed Password Attempts - Check if pam_faillock.so
      even_deny_root parameter is already enabled in pam files
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail).*even_deny_root
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_even_deny_root_parameter_is_present

  - name: Configure the root Account for Failed Password Attempts - Ensure the inclusion
      of pam_faillock.so preauth even_deny_root parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
      line: \1required\3 even_deny_root
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_even_deny_root_parameter_is_present.found == 0

  - name: Configure the root Account for Failed Password Attempts - Ensure the inclusion
      of pam_faillock.so authfail even_deny_root parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
      line: \1required\3 even_deny_root
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_even_deny_root_parameter_is_present.found == 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_faillock_conf_check.stat.exists
  tags:
  - DISA-STIG-OL07-00-010330
  - 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


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

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

authselect apply-changes -b
else
    
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
for pam_file in "${AUTH_FILES[@]}"
do
    if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
        sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
        sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
    fi
    sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
done

fi

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

FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ]; then
    regex="^\s*even_deny_root"
    line="even_deny_root"
    if ! grep -q $regex $FAILLOCK_CONF; then
        echo $line >> $FAILLOCK_CONF
    fi
    for pam_file in "${AUTH_FILES[@]}"
    do
        if [ -e "$pam_file" ] ; then
            PAM_FILE_PATH="$pam_file"
            if [ -f /usr/bin/authselect ]; then
                
                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

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

                authselect apply-changes -b
            fi
            
        if grep -qP '^\s*auth\s.*\bpam_faillock.so\s.*\beven_deny_root\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks 's/(.*auth.*pam_faillock.so.*)\beven_deny_root\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then
                
                authselect apply-changes -b
            fi
        else
            echo "$pam_file was not found" >&2
        fi
    done
else
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth.*pam_faillock\.so (preauth|authfail).*even_deny_root' "$pam_file"; then
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*silent.*/ s/$/ even_deny_root/' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ even_deny_root/' "$pam_file"
        fi
    done
fi

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

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.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
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:  BP28(R18), 1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, OL07-00-010320, SV-221690r880681_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Check if system relies
    on authselect tool
  ansible.builtin.stat:
    path: /usr/bin/authselect
  register: result_authselect_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Remediation where authselect
    tool is present
  block:

  - name: Set Interval For Counting Failed Password Attempts - Check integrity of
      authselect current profile
    ansible.builtin.command:
      cmd: authselect check
    register: result_authselect_check_cmd
    changed_when: false
    failed_when: false

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

  - name: Set Interval For Counting Failed Password Attempts - Get authselect current
      features
    ansible.builtin.shell:
      cmd: authselect current | tail -n+3 | awk '{ print $2 }'
    register: result_authselect_features
    changed_when: false
    when:
    - result_authselect_check_cmd is success

  - name: Set Interval For Counting Failed Password Attempts - Ensure "with-faillock"
      feature is enabled using authselect tool
    ansible.builtin.command:
      cmd: authselect enable-feature with-faillock
    register: result_authselect_enable_feature_cmd
    when:
    - result_authselect_check_cmd is success
    - result_authselect_features.stdout is not search("with-faillock")

  - name: Set Interval For Counting Failed Password Attempts - Ensure authselect changes
      are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_enable_feature_cmd is not skipped
    - result_authselect_enable_feature_cmd is success
  when:
  - '"pam" in ansible_facts.packages'
  - result_authselect_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Remediation where authselect
    tool is not present
  block:

  - name: Set Interval For Counting Failed Password Attempts - Check if pam_faillock.so
      is already enabled
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail)
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_is_enabled

  - name: Set Interval For Counting Failed Password Attempts - Enable pam_faillock.so
      preauth editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so preauth
      insertbefore: ^auth.*sufficient.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Set Interval For Counting Failed Password Attempts - Enable pam_faillock.so
      authfail editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so authfail
      insertbefore: ^auth.*required.*pam_deny\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Set Interval For Counting Failed Password Attempts - Enable pam_faillock.so
      account section editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: account     required      pam_faillock.so
      insertbefore: ^account.*required.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_authselect_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Check the presence of
    /etc/security/faillock.conf file
  ansible.builtin.stat:
    path: /etc/security/faillock.conf
  register: result_faillock_conf_check
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Ensure the pam_faillock.so
    fail_interval parameter in /etc/security/faillock.conf
  ansible.builtin.lineinfile:
    path: /etc/security/faillock.conf
    regexp: ^\s*fail_interval\s*=
    line: fail_interval = {{ var_accounts_passwords_pam_faillock_fail_interval }}
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Ensure the pam_faillock.so
    fail_interval parameter not in PAM files
  block:

  - name: Set Interval For Counting Failed Password Attempts - Check if /etc/pam.d/system-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/system-auth
    register: result_pam_file_present

  - name: Set Interval For Counting Failed Password Attempts - Check the proper remediation
      for the system
    block:

    - name: Set Interval For Counting Failed Password Attempts - Define the PAM file
        to be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/system-auth

    - name: Set Interval For Counting Failed Password Attempts - Check if system relies
        on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
        custom profile is used if authselect is present
      block:

      - name: Set Interval For Counting Failed Password Attempts - Check integrity
          of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Set Interval For Counting Failed Password Attempts - Get authselect
          current profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Set Interval For Counting Failed Password Attempts - Define the current
          authselect profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

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

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

      - name: Set Interval For Counting Failed Password Attempts - Check if any custom
          profile with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Set Interval For Counting Failed Password Attempts - Create an authselect
          custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Interval For Counting Failed Password Attempts - Ensure the authselect
          custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Interval For Counting Failed Password Attempts - Restore the authselect
          features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Set Interval For Counting Failed Password Attempts - Change the PAM
          file to be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Set Interval For Counting Failed Password Attempts - Ensure the "fail_interval"
        option from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\bfail_interval\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists

  - name: Set Interval For Counting Failed Password Attempts - Check if /etc/pam.d/password-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/password-auth
    register: result_pam_file_present

  - name: Set Interval For Counting Failed Password Attempts - Check the proper remediation
      for the system
    block:

    - name: Set Interval For Counting Failed Password Attempts - Define the PAM file
        to be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/password-auth

    - name: Set Interval For Counting Failed Password Attempts - Check if system relies
        on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
        custom profile is used if authselect is present
      block:

      - name: Set Interval For Counting Failed Password Attempts - Check integrity
          of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Set Interval For Counting Failed Password Attempts - Get authselect
          current profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Set Interval For Counting Failed Password Attempts - Define the current
          authselect profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

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

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

      - name: Set Interval For Counting Failed Password Attempts - Check if any custom
          profile with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Set Interval For Counting Failed Password Attempts - Create an authselect
          custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Interval For Counting Failed Password Attempts - Ensure the authselect
          custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Interval For Counting Failed Password Attempts - Restore the authselect
          features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
          changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Set Interval For Counting Failed Password Attempts - Change the PAM
          file to be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Set Interval For Counting Failed Password Attempts - Ensure the "fail_interval"
        option from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\bfail_interval\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Set Interval For Counting Failed Password Attempts - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - DISA-STIG-OL07-00-010320
  - 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: Set Interval For Counting Failed Password Attempts - Ensure the pam_faillock.so
    fail_interval parameter in PAM files
  block:

  - name: Set Interval For Counting Failed Password Attempts - Check if pam_faillock.so
      fail_interval parameter is already enabled in pam files
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail).*fail_interval
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_fail_interval_parameter_is_present

  - name: Set Interval For Counting Failed Password Attempts - Ensure the inclusion
      of pam_faillock.so preauth fail_interval parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
      line: \1required\3 fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
        }}
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_fail_interval_parameter_is_present.found == 0

  - name: Set Interval For Counting Failed Password Attempts - Ensure the inclusion
      of pam_faillock.so authfail fail_interval parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
      line: \1required\3 fail_interval={{ var_accounts_passwords_pam_faillock_fail_interval
        }}
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_fail_interval_parameter_is_present.found == 0

  - name: Set Interval For Counting Failed Password Attempts - Ensure the desired
      value for pam_faillock.so preauth fail_interval parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)(fail_interval)=[0-9]+(.*)
      line: \1required\3\4={{ var_accounts_passwords_pam_faillock_fail_interval }}\5
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_fail_interval_parameter_is_present.found > 0

  - name: Set Interval For Counting Failed Password Attempts - Ensure the desired
      value for pam_faillock.so authfail fail_interval parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)(fail_interval)=[0-9]+(.*)
      line: \1required\3\4={{ var_accounts_passwords_pam_faillock_fail_interval }}\5
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_fail_interval_parameter_is_present.found > 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_faillock_conf_check.stat.exists
  tags:
  - DISA-STIG-OL07-00-010320
  - 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


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

var_accounts_passwords_pam_faillock_fail_interval='900'


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

authselect apply-changes -b
else
    
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
for pam_file in "${AUTH_FILES[@]}"
do
    if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
        sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
        sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
    fi
    sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
done

fi

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

FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ]; then
    regex="^\s*fail_interval\s*="
    line="fail_interval = $var_accounts_passwords_pam_faillock_fail_interval"
    if ! grep -q $regex $FAILLOCK_CONF; then
        echo $line >> $FAILLOCK_CONF
    else
        sed -i --follow-symlinks 's|^\s*\(fail_interval\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_fail_interval"'|g' $FAILLOCK_CONF
    fi
    for pam_file in "${AUTH_FILES[@]}"
    do
        if [ -e "$pam_file" ] ; then
            PAM_FILE_PATH="$pam_file"
            if [ -f /usr/bin/authselect ]; then
                
                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

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

                authselect apply-changes -b
            fi
            
        if grep -qP '^\s*auth\s.*\bpam_faillock.so\s.*\bfail_interval\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks 's/(.*auth.*pam_faillock.so.*)\bfail_interval\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then
                
                authselect apply-changes -b
            fi
        else
            echo "$pam_file was not found" >&2
        fi
    done
else
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth.*pam_faillock\.so (preauth|authfail).*fail_interval' "$pam_file"; then
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*silent.*/ s/$/ fail_interval='"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ fail_interval='"$var_accounts_passwords_pam_faillock_fail_interval"'/' "$pam_file"
        else
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*silent.*\)\('"fail_interval"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_fail_interval"'\3/' "$pam_file"
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"fail_interval"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_fail_interval"'\3/' "$pam_file"
        fi
    done
fi

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

Rule   Set Lockout Time for Failed Password Attempts   [ref]

This rule configures the system to lock out accounts during a specified time period after a number of incorrect login attempts using pam_faillock.so. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid any errors when manually editing these files, it is recommended to use the appropriate tools, such as authselect or authconfig, depending on the OS version. If unlock_time is set to 0, manual intervention by an administrator is required to unlock a user. This should be done using the faillock tool.
Warning:  If the system supports the new /etc/security/faillock.conf file but the pam_faillock.so parameters are defined directly in /etc/pam.d/system-auth and /etc/pam.d/password-auth, the remediation will migrate the unlock_time parameter to /etc/security/faillock.conf to ensure compatibility with authselect tool. The parameters deny and fail_interval, if used, also have to be migrated by their respective remediation.
Warning:  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
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_unlock_time
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(b), PR.AC-7, FIA_AFL.1, Req-8.1.7, 8.3.4, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, OL07-00-010320, SV-221690r880681_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Lockout Time for Failed Password Attempts - Check if system relies on
    authselect tool
  ansible.builtin.stat:
    path: /usr/bin/authselect
  register: result_authselect_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Lockout Time for Failed Password Attempts - Remediation where authselect
    tool is present
  block:

  - name: Set Lockout Time for Failed Password Attempts - Check integrity of authselect
      current profile
    ansible.builtin.command:
      cmd: authselect check
    register: result_authselect_check_cmd
    changed_when: false
    failed_when: false

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

  - name: Set Lockout Time for Failed Password Attempts - Get authselect current features
    ansible.builtin.shell:
      cmd: authselect current | tail -n+3 | awk '{ print $2 }'
    register: result_authselect_features
    changed_when: false
    when:
    - result_authselect_check_cmd is success

  - name: Set Lockout Time for Failed Password Attempts - Ensure "with-faillock" feature
      is enabled using authselect tool
    ansible.builtin.command:
      cmd: authselect enable-feature with-faillock
    register: result_authselect_enable_feature_cmd
    when:
    - result_authselect_check_cmd is success
    - result_authselect_features.stdout is not search("with-faillock")

  - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
      are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_enable_feature_cmd is not skipped
    - result_authselect_enable_feature_cmd is success
  when:
  - '"pam" in ansible_facts.packages'
  - result_authselect_present.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Lockout Time for Failed Password Attempts - Remediation where authselect
    tool is not present
  block:

  - name: Set Lockout Time for Failed Password Attempts - Check if pam_faillock.so
      is already enabled
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail)
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_is_enabled

  - name: Set Lockout Time for Failed Password Attempts - Enable pam_faillock.so preauth
      editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so preauth
      insertbefore: ^auth.*sufficient.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Set Lockout Time for Failed Password Attempts - Enable pam_faillock.so authfail
      editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: auth        required      pam_faillock.so authfail
      insertbefore: ^auth.*required.*pam_deny\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0

  - name: Set Lockout Time for Failed Password Attempts - Enable pam_faillock.so account
      section editing PAM files
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      line: account     required      pam_faillock.so
      insertbefore: ^account.*required.*pam_unix\.so.*
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_is_enabled.found == 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_authselect_present.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - 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 900
  tags:
    - always

- name: Set Lockout Time for Failed Password Attempts - Check the presence of /etc/security/faillock.conf
    file
  ansible.builtin.stat:
    path: /etc/security/faillock.conf
  register: result_faillock_conf_check
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Lockout Time for Failed Password Attempts - Ensure the pam_faillock.so
    unlock_time parameter in /etc/security/faillock.conf
  ansible.builtin.lineinfile:
    path: /etc/security/faillock.conf
    regexp: ^\s*unlock_time\s*=
    line: unlock_time = {{ var_accounts_passwords_pam_faillock_unlock_time }}
    state: present
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Lockout Time for Failed Password Attempts - Ensure the pam_faillock.so
    unlock_time parameter not in PAM files
  block:

  - name: Set Lockout Time for Failed Password Attempts - Check if /etc/pam.d/system-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/system-auth
    register: result_pam_file_present

  - name: Set Lockout Time for Failed Password Attempts - Check the proper remediation
      for the system
    block:

    - name: Set Lockout Time for Failed Password Attempts - Define the PAM file to
        be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/system-auth

    - name: Set Lockout Time for Failed Password Attempts - Check if system relies
        on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Set Lockout Time for Failed Password Attempts - Ensure authselect custom
        profile is used if authselect is present
      block:

      - name: Set Lockout Time for Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Set Lockout Time for Failed Password Attempts - Get authselect current
          profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Set Lockout Time for Failed Password Attempts - Define the current authselect
          profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

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

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

      - name: Set Lockout Time for Failed Password Attempts - Check if any custom
          profile with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Set Lockout Time for Failed Password Attempts - Create an authselect
          custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Lockout Time for Failed Password Attempts - Ensure the authselect
          custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Lockout Time for Failed Password Attempts - Restore the authselect
          features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Set Lockout Time for Failed Password Attempts - Change the PAM file
          to be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Set Lockout Time for Failed Password Attempts - Ensure the "unlock_time"
        option from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\bunlock_time\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
        are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists

  - name: Set Lockout Time for Failed Password Attempts - Check if /etc/pam.d/password-auth
      file is present
    ansible.builtin.stat:
      path: /etc/pam.d/password-auth
    register: result_pam_file_present

  - name: Set Lockout Time for Failed Password Attempts - Check the proper remediation
      for the system
    block:

    - name: Set Lockout Time for Failed Password Attempts - Define the PAM file to
        be edited as a local fact
      ansible.builtin.set_fact:
        pam_file_path: /etc/pam.d/password-auth

    - name: Set Lockout Time for Failed Password Attempts - Check if system relies
        on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present

    - name: Set Lockout Time for Failed Password Attempts - Ensure authselect custom
        profile is used if authselect is present
      block:

      - name: Set Lockout Time for Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        failed_when: false

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

      - name: Set Lockout Time for Failed Password Attempts - Get authselect current
          profile
        ansible.builtin.shell:
          cmd: authselect current -r | awk '{ print $1 }'
        register: result_authselect_profile
        changed_when: false
        when:
        - result_authselect_check_cmd is success

      - name: Set Lockout Time for Failed Password Attempts - Define the current authselect
          profile as a local fact
        ansible.builtin.set_fact:
          authselect_current_profile: '{{ result_authselect_profile.stdout }}'
          authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
        when:
        - result_authselect_profile is not skipped
        - result_authselect_profile.stdout is match("custom/")

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

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

      - name: Set Lockout Time for Failed Password Attempts - Check if any custom
          profile with the same name was already created
        ansible.builtin.stat:
          path: /etc/authselect/{{ authselect_custom_profile }}
        register: result_authselect_custom_profile_present
        changed_when: false
        when:
        - authselect_current_profile is not match("custom/")

      - name: Set Lockout Time for Failed Password Attempts - Create an authselect
          custom profile based on the current profile
        ansible.builtin.command:
          cmd: authselect create-profile hardening -b {{ authselect_current_profile
            }}
        when:
        - result_authselect_check_cmd is success
        - authselect_current_profile is not match("custom/")
        - not result_authselect_custom_profile_present.stat.exists

      - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Lockout Time for Failed Password Attempts - Ensure the authselect
          custom profile is selected
        ansible.builtin.command:
          cmd: authselect select {{ authselect_custom_profile }}
        register: result_pam_authselect_select_profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - authselect_current_profile is not match("custom/")
        - authselect_custom_profile is not match(authselect_current_profile)

      - name: Set Lockout Time for Failed Password Attempts - Restore the authselect
          features in the custom profile
        ansible.builtin.command:
          cmd: authselect enable-feature {{ item }}
        loop: '{{ result_authselect_features.stdout_lines }}'
        register: result_pam_authselect_restore_features
        when:
        - result_authselect_profile is not skipped
        - result_authselect_features is not skipped
        - result_pam_authselect_select_profile is not skipped

      - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
        when:
        - result_authselect_check_cmd is success
        - result_authselect_profile is not skipped
        - result_pam_authselect_restore_features is not skipped

      - name: Set Lockout Time for Failed Password Attempts - Change the PAM file
          to be edited according to the custom authselect profile
        ansible.builtin.set_fact:
          pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
            | basename }}
      when:
      - result_authselect_present.stat.exists

    - name: Set Lockout Time for Failed Password Attempts - Ensure the "unlock_time"
        option from "pam_faillock.so" is not present in {{ pam_file_path }}
      ansible.builtin.replace:
        dest: '{{ pam_file_path }}'
        regexp: (.*auth.*pam_faillock.so.*)\bunlock_time\b=?[0-9a-zA-Z]*(.*)
        replace: \1\2
      register: result_pam_option_removal

    - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
        are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b
      when:
      - result_authselect_present.stat.exists
      - result_pam_option_removal is changed
    when:
    - result_pam_file_present.stat.exists
  when:
  - '"pam" in ansible_facts.packages'
  - result_faillock_conf_check.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Lockout Time for Failed Password Attempts - Ensure the pam_faillock.so
    unlock_time parameter in PAM files
  block:

  - name: Set Lockout Time for Failed Password Attempts - Check if pam_faillock.so
      unlock_time parameter is already enabled in pam files
    ansible.builtin.lineinfile:
      path: /etc/pam.d/system-auth
      regexp: .*auth.*pam_faillock\.so (preauth|authfail).*unlock_time
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_faillock_unlock_time_parameter_is_present

  - name: Set Lockout Time for Failed Password Attempts - Ensure the inclusion of
      pam_faillock.so preauth unlock_time parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
      line: \1required\3 unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
        }}
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_unlock_time_parameter_is_present.found == 0

  - name: Set Lockout Time for Failed Password Attempts - Ensure the inclusion of
      pam_faillock.so authfail unlock_time parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
      line: \1required\3 unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
        }}
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_unlock_time_parameter_is_present.found == 0

  - name: Set Lockout Time for Failed Password Attempts - Ensure the desired value
      for pam_faillock.so preauth unlock_time parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)(unlock_time)=[0-9]+(.*)
      line: \1required\3\4={{ var_accounts_passwords_pam_faillock_unlock_time }}\5
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_unlock_time_parameter_is_present.found > 0

  - name: Set Lockout Time for Failed Password Attempts - Ensure the desired value
      for pam_faillock.so authfail unlock_time parameter in auth section
    ansible.builtin.lineinfile:
      path: '{{ item }}'
      backrefs: true
      regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)(unlock_time)=[0-9]+(.*)
      line: \1required\3\4={{ var_accounts_passwords_pam_faillock_unlock_time }}\5
      state: present
    loop:
    - /etc/pam.d/system-auth
    - /etc/pam.d/password-auth
    when:
    - result_pam_faillock_unlock_time_parameter_is_present.found > 0
  when:
  - '"pam" in ansible_facts.packages'
  - not result_faillock_conf_check.stat.exists
  tags:
  - CJIS-5.5.3
  - DISA-STIG-OL07-00-010320
  - NIST-800-171-3.1.8
  - NIST-800-53-AC-7(b)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.1.7
  - PCI-DSSv4-8.3.4
  - accounts_passwords_pam_faillock_unlock_time
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


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

var_accounts_passwords_pam_faillock_unlock_time='900'


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

authselect apply-changes -b
else
    
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
for pam_file in "${AUTH_FILES[@]}"
do
    if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
        sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
        sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
        sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
    fi
    sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
done

fi

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

FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ]; then
    regex="^\s*unlock_time\s*="
    line="unlock_time = $var_accounts_passwords_pam_faillock_unlock_time"
    if ! grep -q $regex $FAILLOCK_CONF; then
        echo $line >> $FAILLOCK_CONF
    else
        sed -i --follow-symlinks 's|^\s*\(unlock_time\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_unlock_time"'|g' $FAILLOCK_CONF
    fi
    for pam_file in "${AUTH_FILES[@]}"
    do
        if [ -e "$pam_file" ] ; then
            PAM_FILE_PATH="$pam_file"
            if [ -f /usr/bin/authselect ]; then
                
                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

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

                authselect apply-changes -b
            fi
            
        if grep -qP '^\s*auth\s.*\bpam_faillock.so\s.*\bunlock_time\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks 's/(.*auth.*pam_faillock.so.*)\bunlock_time\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then
                
                authselect apply-changes -b
            fi
        else
            echo "$pam_file was not found" >&2
        fi
    done
else
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth.*pam_faillock\.so (preauth|authfail).*unlock_time' "$pam_file"; then
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*silent.*/ s/$/ unlock_time='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ unlock_time='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
        else
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*silent.*\)\('"unlock_time"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'\3/' "$pam_file"
            sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"unlock_time"'=\)[0-9]\+\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'\3/' "$pam_file"
        fi
    done
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Set Password Quality Requirements   Group contains 1 group and 5 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 5 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 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:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000194, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, 8.3.9, SRG-OS-000071-GPOS-00039, OL07-00-010140, SV-221671r603260_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-010140
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_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 Enforces Password Requirements - Minimum Digit Characters - Check
    if /etc/pam.d/system-auth file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010140
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Check
    the proper remediation for the system
  block:

  - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Define
      the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Check
      if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Ensure
      authselect custom profile is used if authselect is present
    block:

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Check integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Get authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Define the current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Define the new authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Check if any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Create an authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Ensure the authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Restore the authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters -
        Change the PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Ensure
      the "dcredit" option from "pam_pwquality.so" is not present in {{ pam_file_path
      }}
    ansible.builtin.replace:
      dest: '{{ pam_file_path }}'
      regexp: (.*password.*pam_pwquality.so.*)\bdcredit\b=?[0-9a-zA-Z]*(.*)
      replace: \1\2
    register: result_pam_option_removal

  - name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Ensure
      authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - result_pam_option_removal is changed
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010140
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Ensure
    PAM variable dcredit is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*dcredit
    line: dcredit = {{ var_password_pam_dcredit }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010140
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_dcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

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

var_password_pam_dcredit='-1'





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

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

        authselect apply-changes -b
    fi
    
if grep -qP '^\s*password\s.*\bpam_pwquality.so\s.*\bdcredit\b' "$PAM_FILE_PATH"; then
    sed -i -E --follow-symlinks 's/(.*password.*pam_pwquality.so.*)\bdcredit\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi


# 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' <<< "^dcredit")

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

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

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

Rule   Ensure PAM Enforces Password Requirements - Minimum 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:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, 8.3.9, SRG-OS-000070-GPOS-00038, OL07-00-010130, SV-221670r603260_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-010130
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_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 Enforces Password Requirements - Minimum Lowercase Characters -
    Check if /etc/pam.d/system-auth file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010130
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters -
    Check the proper remediation for the system
  block:

  - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
      - Define the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
      - Check if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
      - Ensure authselect custom profile is used if authselect is present
    block:

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Check integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Get authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Define the current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Define the new authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Check if any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Create an authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Ensure the authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Restore the authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
        - Change the PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
      - Ensure the "lcredit" option from "pam_pwquality.so" is not present in {{ pam_file_path
      }}
    ansible.builtin.replace:
      dest: '{{ pam_file_path }}'
      regexp: (.*password.*pam_pwquality.so.*)\blcredit\b=?[0-9a-zA-Z]*(.*)
      replace: \1\2
    register: result_pam_option_removal

  - name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
      - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - result_pam_option_removal is changed
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010130
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters -
    Ensure PAM variable lcredit is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*lcredit
    line: lcredit = {{ var_password_pam_lcredit }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010130
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_lcredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

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

var_password_pam_lcredit='-1'





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

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

        authselect apply-changes -b
    fi
    
if grep -qP '^\s*password\s.*\bpam_pwquality.so\s.*\blcredit\b' "$PAM_FILE_PATH"; then
    sed -i -E --follow-symlinks 's/(.*password.*pam_pwquality.so.*)\blcredit\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi


# 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' <<< "^lcredit")

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

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

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

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

The pam_pwquality module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=18 after pam_pwquality to set minimum password length requirements.
Rationale:
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000205, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, 8.3.9, SRG-OS-000078-GPOS-00046, OL07-00-010280, SV-221686r603260_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.1.1
  - DISA-STIG-OL07-00-010280
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
- name: XCCDF Value var_password_pam_minlen # promote to variable
  set_fact:
    var_password_pam_minlen: !!str 18
  tags:
    - always

- name: Ensure PAM Enforces Password Requirements - Minimum Length - Check if /etc/pam.d/system-auth
    file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.1.1
  - DISA-STIG-OL07-00-010280
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Length - Check the proper
    remediation for the system
  block:

  - name: Ensure PAM Enforces Password Requirements - Minimum Length - Define the
      PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Ensure PAM Enforces Password Requirements - Minimum Length - Check if system
      relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure authselect
      custom profile is used if authselect is present
    block:

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Check integrity
        of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Get authselect
        current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Define the
        current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

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

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Check if
        any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Create an
        authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure the
        authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Restore the
        authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Change the
        PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure the
      "minlen" option from "pam_pwquality.so" is not present in {{ pam_file_path }}
    ansible.builtin.replace:
      dest: '{{ pam_file_path }}'
      regexp: (.*password.*pam_pwquality.so.*)\bminlen\b=?[0-9a-zA-Z]*(.*)
      replace: \1\2
    register: result_pam_option_removal

  - name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure authselect
      changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - result_pam_option_removal is changed
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - CJIS-5.6.2.1.1
  - DISA-STIG-OL07-00-010280
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure PAM variable
    minlen is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*minlen
    line: minlen = {{ var_password_pam_minlen }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.1.1
  - DISA-STIG-OL07-00-010280
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_minlen
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

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

var_password_pam_minlen='18'





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

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

        authselect apply-changes -b
    fi
    
if grep -qP '^\s*password\s.*\bpam_pwquality.so\s.*\bminlen\b' "$PAM_FILE_PATH"; then
    sed -i -E --follow-symlinks 's/(.*password.*pam_pwquality.so.*)\bminlen\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi


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

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

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

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

Rule   Ensure PAM 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 possible 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:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-001619, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, SRG-OS-000266-GPOS-00101, OL07-00-010150, SV-221672r603260_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-010150
  - 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 Enforces Password Requirements - Minimum Special Characters - Check
    if /etc/pam.d/system-auth file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010150
  - 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: Ensure PAM Enforces Password Requirements - Minimum Special Characters - Check
    the proper remediation for the system
  block:

  - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters -
      Define the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters -
      Check if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters -
      Ensure authselect custom profile is used if authselect is present
    block:

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Check integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Get authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Define the current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Define the new authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Check if any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Create an authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Ensure the authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Restore the authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters
        - Change the PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters -
      Ensure the "ocredit" option from "pam_pwquality.so" is not present in {{ pam_file_path
      }}
    ansible.builtin.replace:
      dest: '{{ pam_file_path }}'
      regexp: (.*password.*pam_pwquality.so.*)\bocredit\b=?[0-9a-zA-Z]*(.*)
      replace: \1\2
    register: result_pam_option_removal

  - name: Ensure PAM Enforces Password Requirements - Minimum Special Characters -
      Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - result_pam_option_removal is changed
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010150
  - 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: Ensure PAM Enforces Password Requirements - Minimum Special Characters - Ensure
    PAM variable ocredit is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*ocredit
    line: ocredit = {{ var_password_pam_ocredit }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010150
  - 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

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

var_password_pam_ocredit='-1'





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

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

        authselect apply-changes -b
    fi
    
if grep -qP '^\s*password\s.*\bpam_pwquality.so\s.*\bocredit\b' "$PAM_FILE_PATH"; then
    sed -i -E --follow-symlinks 's/(.*password.*pam_pwquality.so.*)\bocredit\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi


# 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' <<< "^ocredit")

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

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

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

Rule   Ensure PAM Enforces Password Requirements - Minimum 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 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.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_ucredit
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, 8.3.6, 8.3.9, SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038, OL07-00-010120, SV-221669r603260_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-010120
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_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 Enforces Password Requirements - Minimum Uppercase Characters -
    Check if /etc/pam.d/system-auth file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010120
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters -
    Check the proper remediation for the system
  block:

  - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
      - Define the PAM file to be edited as a local fact
    ansible.builtin.set_fact:
      pam_file_path: /etc/pam.d/system-auth

  - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
      - Check if system relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
      - Ensure authselect custom profile is used if authselect is present
    block:

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Check integrity of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Get authselect current profile
      ansible.builtin.shell:
        cmd: authselect current -r | awk '{ print $1 }'
      register: result_authselect_profile
      changed_when: false
      when:
      - result_authselect_check_cmd is success

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Define the current authselect profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Define the new authselect custom profile as a local fact
      ansible.builtin.set_fact:
        authselect_current_profile: '{{ result_authselect_profile.stdout }}'
        authselect_custom_profile: custom/hardening
      when:
      - result_authselect_profile is not skipped
      - result_authselect_profile.stdout is not match("custom/")

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

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Check if any custom profile with the same name was already created
      ansible.builtin.stat:
        path: /etc/authselect/{{ authselect_custom_profile }}
      register: result_authselect_custom_profile_present
      changed_when: false
      when:
      - authselect_current_profile is not match("custom/")

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Create an authselect custom profile based on the current profile
      ansible.builtin.command:
        cmd: authselect create-profile hardening -b {{ authselect_current_profile
          }}
      when:
      - result_authselect_check_cmd is success
      - authselect_current_profile is not match("custom/")
      - not result_authselect_custom_profile_present.stat.exists

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Ensure the authselect custom profile is selected
      ansible.builtin.command:
        cmd: authselect select {{ authselect_custom_profile }}
      register: result_pam_authselect_select_profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - authselect_current_profile is not match("custom/")
      - authselect_custom_profile is not match(authselect_current_profile)

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Restore the authselect features in the custom profile
      ansible.builtin.command:
        cmd: authselect enable-feature {{ item }}
      loop: '{{ result_authselect_features.stdout_lines }}'
      register: result_pam_authselect_restore_features
      when:
      - result_authselect_profile is not skipped
      - result_authselect_features is not skipped
      - result_pam_authselect_select_profile is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Ensure authselect changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

    - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
        - Change the PAM file to be edited according to the custom authselect profile
      ansible.builtin.set_fact:
        pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
          | basename }}
    when:
    - result_authselect_present.stat.exists

  - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
      - Ensure the "ucredit" option from "pam_pwquality.so" is not present in {{ pam_file_path
      }}
    ansible.builtin.replace:
      dest: '{{ pam_file_path }}'
      regexp: (.*password.*pam_pwquality.so.*)\bucredit\b=?[0-9a-zA-Z]*(.*)
      replace: \1\2
    register: result_pam_option_removal

  - name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
      - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - result_pam_option_removal is changed
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - DISA-STIG-OL07-00-010120
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters -
    Ensure PAM variable ucredit is set accordingly
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/security/pwquality.conf
    regexp: ^#?\s*ucredit
    line: ucredit = {{ var_password_pam_ucredit }}
  when: '"pam" in ansible_facts.packages'
  tags:
  - DISA-STIG-OL07-00-010120
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(a)
  - NIST-800-53-IA-5(4)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.3
  - PCI-DSSv4-8.3.6
  - PCI-DSSv4-8.3.9
  - accounts_password_pam_ucredit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

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

var_password_pam_ucredit='-1'





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

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

        authselect apply-changes -b
    fi
    
if grep -qP '^\s*password\s.*\bpam_pwquality.so\s.*\bucredit\b' "$PAM_FILE_PATH"; then
    sed -i -E --follow-symlinks 's/(.*password.*pam_pwquality.so.*)\bucredit\b=?[[:alnum:]]*(.*)/\1\2/g' "$PAM_FILE_PATH"
fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi


# 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' <<< "^ucredit")

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

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

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Set Password Hashing Algorithm   Group contains 1 rule
[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:  BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, CCI-000803, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 8.3.2, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061, OL07-00-010200, SV-221677r880672_rule


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.6.2.2
  - DISA-STIG-OL07-00-010200
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

- name: Set PAM's Password Hashing Algorithm - Check if /etc/pam.d/system-auth file
    is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - CJIS-5.6.2.2
  - DISA-STIG-OL07-00-010200
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  - name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam_sha512_add is defined and result_pam_sha512_add.changed)
       or (result_pam_sha512_edit is defined and result_pam_sha512_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - CJIS-5.6.2.2
  - DISA-STIG-OL07-00-010200
  - NIST-800-171-3.13.11
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-IA-5(c)
  - PCI-DSS-Req-8.2.1
  - PCI-DSSv4-8.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - set_password_hashing_algorithm_systemauth


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

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

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

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

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

Rule   Set Up a Private Namespace in PAM Configuration   [ref]

To setup a private namespace add the following line to /etc/pam.d/login: 
session    required     pam_namespace.so
Rationale:
The pam_namespace PAM module sets up a private namespace for a session with polyinstantiated directories. A polyinstantiated directory provides a different instance of itself based on user name, or when using SELinux, user name, security context or both. The polyinstatied directories can be used to dedicate separate temporary directories to each account.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_enable_pam_namespace
Identifiers and References

References:  BP28(R39)


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - enable_pam_namespace
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy

- name: Make changes to /etc/pam.d/login
  lineinfile:
    path: /etc/pam.d/login
    create: false
    regexp: ^\s*session\s+required\s+pam_namespace.so\s*$
    line: session    required     pam_namespace.so
    state: present
  when: ( not ( lookup("env", "container") == "bwrap-osbuild" ) and "pam" in ansible_facts.packages
    )
  tags:
  - enable_pam_namespace
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - restrict_strategy


# Remediation is applicable only in certain platforms
if ( ! ( [ "${container:-}" == "bwrap-osbuild" ] ) && rpm --quiet -q pam ); then

if ! grep -Eq '^\s*session\s+required\s+pam_namespace.so\s*$' '/etc/pam.d/login' ; then
    echo "session    required     pam_namespace.so" >> "/etc/pam.d/login"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Protect Accounts by Restricting Password-Based Login   Group contains 3 groups and 5 rules
[ref]   Conventionally, Unix shell accounts are accessed by providing a username and password to a login program, which tests these values for correctness using the /etc/passwd and /etc/shadow files. Password-based login is vulnerable to guessing of weak passwords, and to sniffing and man-in-the-middle attacks against passwords entered over a network or at an insecure console. Therefore, mechanisms for accessing accounts by entering usernames and passwords should be restricted to those which are operationally necessary.
Group   Set 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   Verify Proper Storage and Existence of Password Hashes   Group contains 2 rules
[ref]   By default, password hashes for local accounts are stored in the second field (colon-separated) in /etc/shadow. This file should be readable only by processes running with root credentials, preventing users from casually accessing others' password hashes and attempting to crack them. However, it remains possible to misconfigure the system and store password hashes in world-readable files such as /etc/passwd, or to even store passwords themselves in plaintext on the system. Using system-provided tools for password change/creation should allow administrators to avoid such misconfiguration.

Rule   Set number of Password Hashing Rounds - password-auth   [ref]

Configure the number or rounds for the password hashing algorithm. This can be accomplished by using the rounds option for the pam_unix PAM module.

In file /etc/pam.d/password-auth append rounds=65536 to the pam_unix.so entry, as shown below: 
password sufficient pam_unix.so ...existing_options... rounds=65536
The system's default number of rounds is 5000.
Warning:  Setting a high number of hashing rounds makes it more difficult to brute force the password, but requires more CPU resources to authenticate users.
Rationale:
Using a higher number of rounds makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_unix_rounds_password_auth
Identifiers and References

References:  BP28(R32), CCI-000196, SRG-OS-000073-GPOS-00041


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - accounts_password_pam_unix_rounds_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_password_pam_unix_rounds # promote to variable
  set_fact:
    var_password_pam_unix_rounds: !!str 65536
  tags:
    - always

- name: Set number of Password Hashing Rounds - password-auth - Check if /etc/pam.d/password-auth
    file is present
  ansible.builtin.stat:
    path: /etc/pam.d/password-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - accounts_password_pam_unix_rounds_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Set number of Password Hashing Rounds - password-auth - Check the proper remediation
    for the system
  block:

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

  - name: Set number of Password Hashing Rounds - password-auth - Check if system
      relies on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Set number of Password Hashing Rounds - password-auth - Ensure authselect
      custom profile is used if authselect is present
    block:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  - name: Set number of Password Hashing Rounds - password-auth - Include or update
      the PAM module line in {{ pam_file_path }}
    block:

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

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

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

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

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

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

  - name: Set number of Password Hashing Rounds - password-auth - Ensure the required
      value for "rounds" PAM option from "pam_unix.so" in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+sufficient\s+pam_unix.so\s+.*)(rounds)=[0-9a-zA-Z]+\s*(.*)
      line: \1\2={{ var_password_pam_unix_rounds }} \3
    register: result_pam_rounds_edit
    when:
    - result_pam_module_rounds_option_present.found > 0

  - name: Set number of Password Hashing Rounds - password-auth - Ensure authselect
      changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam_rounds_add is defined and result_pam_rounds_add.changed)
       or (result_pam_rounds_edit is defined and result_pam_rounds_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - accounts_password_pam_unix_rounds_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed


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

var_password_pam_unix_rounds='65536'



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

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

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
            else
                echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\srounds\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ rounds='"$var_password_pam_unix_rounds"'/' "$PAM_FILE_PATH"
        else
            sed -i -E --follow-symlinks 's/(\s*password\s+'"sufficient"'\s+pam_unix.so\s+.*)('"rounds"'=)[[:alnum:]]+\s*(.*)/\1\2'"$var_password_pam_unix_rounds"' \3/' "$PAM_FILE_PATH"
        fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/password-auth was not found" >&2
fi

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

Rule   Set number of Password Hashing Rounds - system-auth   [ref]

Configure the number or rounds for the password hashing algorithm. This can be accomplished by using the rounds option for the pam_unix PAM module.

In file /etc/pam.d/system-auth append rounds=65536 to the pam_unix.so entry, as shown below: 
password sufficient pam_unix.so ...existing_options... rounds=65536
The system's default number of rounds is 5000.
Warning:  Setting a high number of hashing rounds makes it more difficult to brute force the password, but requires more CPU resources to authenticate users.
Rationale:
Using a higher number of rounds makes password cracking attacks more difficult.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_password_pam_unix_rounds_system_auth
Identifiers and References

References:  BP28(R32), CCI-000196, SRG-OS-000073-GPOS-00041


Complexity:low
Disruption:medium
Strategy:configure
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - accounts_password_pam_unix_rounds_system_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_password_pam_unix_rounds # promote to variable
  set_fact:
    var_password_pam_unix_rounds: !!str 65536
  tags:
    - always

- name: Set number of Password Hashing Rounds - system-auth - Check if /etc/pam.d/system-auth
    file is present
  ansible.builtin.stat:
    path: /etc/pam.d/system-auth
  register: result_pam_file_present
  when: '"pam" in ansible_facts.packages'
  tags:
  - accounts_password_pam_unix_rounds_system_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: Set number of Password Hashing Rounds - system-auth - Check the proper remediation
    for the system
  block:

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

  - name: Set number of Password Hashing Rounds - system-auth - Check if system relies
      on authselect tool
    ansible.builtin.stat:
      path: /usr/bin/authselect
    register: result_authselect_present

  - name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
      custom profile is used if authselect is present
    block:

    - name: Set number of Password Hashing Rounds - system-auth - Check integrity
        of authselect current profile
      ansible.builtin.command:
        cmd: authselect check
      register: result_authselect_check_cmd
      changed_when: false
      failed_when: false

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

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

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

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

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

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

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

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

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

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

    - name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
        changes are applied
      ansible.builtin.command:
        cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
      when:
      - result_authselect_check_cmd is success
      - result_authselect_profile is not skipped
      - result_pam_authselect_restore_features is not skipped

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

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

  - name: Set number of Password Hashing Rounds - system-auth - Include or update
      the PAM module line in {{ pam_file_path }}
    block:

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

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

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

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

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

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

  - name: Set number of Password Hashing Rounds - system-auth - Ensure the required
      value for "rounds" PAM option from "pam_unix.so" in {{ pam_file_path }}
    ansible.builtin.lineinfile:
      path: '{{ pam_file_path }}'
      backrefs: true
      regexp: ^(\s*password\s+sufficient\s+pam_unix.so\s+.*)(rounds)=[0-9a-zA-Z]+\s*(.*)
      line: \1\2={{ var_password_pam_unix_rounds }} \3
    register: result_pam_rounds_edit
    when:
    - result_pam_module_rounds_option_present.found > 0

  - name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
      changes are applied
    ansible.builtin.command:
      cmd: authselect apply-changes -b
    when:
    - result_authselect_present.stat.exists
    - |-
      (result_pam_rounds_add is defined and result_pam_rounds_add.changed)
       or (result_pam_rounds_edit is defined and result_pam_rounds_edit.changed)
  when:
  - '"pam" in ansible_facts.packages'
  - result_pam_file_present.stat.exists
  tags:
  - accounts_password_pam_unix_rounds_system_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed


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

var_password_pam_unix_rounds='65536'


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

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

        authselect apply-changes -b
    fi
    if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
            else
                echo 'password    '"sufficient"'    pam_unix.so' >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\srounds\b' "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ rounds='"$var_password_pam_unix_rounds"'/' "$PAM_FILE_PATH"
        else
            sed -i -E --follow-symlinks 's/(\s*password\s+'"sufficient"'\s+pam_unix.so\s+.*)('"rounds"'=)[[:alnum:]]+\s*(.*)/\1\2'"$var_password_pam_unix_rounds"' \3/' "$PAM_FILE_PATH"
        fi
    if [ -f /usr/bin/authselect ]; then
        
        authselect apply-changes -b
    fi
else
    echo "/etc/pam.d/system-auth was not found" >&2
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Restrict Root Logins   Group contains 1 rule
[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   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, Oracle Linux 7'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
Warning:  This rule only checks the /etc/securetty file existence and its content. If you need to restrict user access using the /etc/securetty file, make sure the pam_securetty.so PAM module is properly enabled in relevant PAM files.
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:  BP28(R19), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 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), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, 8.6.1


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
  - PCI-DSSv4-8.6.1
  - low_complexity
  - low_disruption
  - medium_severity
  - no_direct_root_logins
  - no_reboot_needed
  - restrict_strategy


# 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
Group   Secure Session Configuration Files for Login Accounts   Group contains 3 rules
[ref]   When a user logs into a Unix account, the system configures the user's session by reading a number of files. Many of these files are located in the user's home directory, and may have weak permissions as a result of user error or misconfiguration. If an attacker can modify or even read certain types of account configuration information, they can often gain full access to the affected user's account. Therefore, it is important to test and correct configuration file permissions for interactive accounts, particularly those of privileged users such as root or system administrators.

Rule   Configure Polyinstantiation of /tmp Directories   [ref]

To configure polyinstantiated /tmp directories, first create the parent directories which will hold the polyinstantiation child directories. Use the following command: 
$ sudo mkdir --mode 000 /tmp/tmp-inst
Then, add the following entry to /etc/security/namespace.conf: 
/tmp     /tmp/tmp-inst/            level      root,adm
Rationale:
Polyinstantiation of temporary directories is a proactive security measure which reduces chances of attacks that are made possible by /tmp directories being world-writable.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_accounts_polyinstantiated_tmp
Identifiers and References

References:  BP28(R39)


# Remediation is applicable only in certain platforms
if ! ( [ "${container:-}" == "bwrap-osbuild" ] ); then

#!/bin/bash

# shellcheck disable=SC2174
mkdir -p --mode 000 /tmp/tmp-inst
chmod 000 /tmp/tmp-inst
chcon --reference=/tmp /tmp/tmp-inst

if ! grep -Eq '^\s*/tmp\s+/tmp/tmp-inst/\s+level\s+root,adm$' /etc/security/namespace.conf ; then
    if grep -Eq '^\s*/tmp\s+' /etc/security/namespace.conf ; then
        sed -i '/^\s*\/tmp/d' /etc/security/namespace.conf
    fi
    echo "/tmp     /tmp/tmp-inst/        level      root,adm" >> /etc/security/namespace.conf
fi

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

Rule   Configure Polyinstantiation of /var/tmp Directories   [ref]

To configure polyinstantiated /tmp directories, first create the parent directories which will hold the polyinstantiation child directories. Use the following command: 
$ sudo mkdir --mode 000 /var/tmp/tmp-inst
Then, add the following entry to /etc/security/namespace.conf: 
/var/tmp /var/tmp/tmp-inst/    level      root,adm
Rationale:
Polyinstantiation of temporary directories is a proactive security measure which reduces chances of attacks that are made possible by /var/tmp directories being world-writable.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_accounts_polyinstantiated_var_tmp
Identifiers and References

References:  BP28(R39)


# Remediation is applicable only in certain platforms
if ! ( [ "${container:-}" == "bwrap-osbuild" ] ); then

#!/bin/bash

# shellcheck disable=SC2174
mkdir -p --mode 000 /var/tmp/tmp-inst
chmod 000 /var/tmp/tmp-inst
chcon --reference=/var/tmp /var/tmp/tmp-inst

if ! grep -Eq '^\s*/var/tmp\s+/var/tmp/tmp-inst/\s+level\s+root,adm$' /etc/security/namespace.conf ; then
    if grep -Eq '^\s*/var/tmp\s+' /etc/security/namespace.conf ; then
        sed -i '/^\s*\/var\/tmp/d' /etc/security/namespace.conf
    fi
    echo "/var/tmp /var/tmp/tmp-inst/    level      root,adm" >> /etc/security/namespace.conf
fi

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

Rule   Set Interactive Session Timeout   [ref]

Setting the TMOUT option in /etc/profile ensures that all user sessions will terminate based on inactivity. The value of TMOUT should be exported and read only. The TMOUT setting in a file loaded by /etc/profileor /etc/bashrc, e.g. /etc/profile.d/tmout.sh should read as follows: 
declare -xr TMOUT=600
Rationale:
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_accounts_tmout
Identifiers and References

References:  BP28(R29), 1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.11, CCI-000057, CCI-001133, CCI-002361, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-12, SC-10, AC-2(5), CM-6(a), PR.AC-7, FMT_MOF_EXT.1, 8.6.1, SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010, OL07-00-040160, SV-221841r858463_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_accounts_tmout # promote to variable
  set_fact:
    var_accounts_tmout: !!str 600
  tags:
    - always

- name: Correct any occurrence of TMOUT in /etc/bashrc
  replace:
    path: /etc/bashrc
    regexp: ^[^#].*TMOUT=.*
    replace: declare -xr TMOUT={{ var_accounts_tmout }}
  register: bashrc_replaced
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040160
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Correct any occurrence of TMOUT in /etc/profile
  replace:
    path: /etc/profile
    regexp: ^[^#].*TMOUT=.*
    replace: declare -xr TMOUT={{ var_accounts_tmout }}
  register: profile_replaced
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040160
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set Interactive Session Timeout
  lineinfile:
    path: /etc/profile.d/tmout.sh
    create: true
    regexp: TMOUT=
    line: declare -xr TMOUT={{ var_accounts_tmout }}
    state: present
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - profile_replaced is defined and not profile_replaced.changed and bashrc_replaced
    is defined and not bashrc_replaced.changed
  tags:
  - DISA-STIG-OL07-00-040160
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSSv4-8.6.1
  - accounts_tmout
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


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

var_accounts_tmout='600'


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


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

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

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

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   System Accounting with auditd   Group contains 2 groups and 1 rule
[ref]   The audit service provides substantial capabilities for recording system activities. By default, the service audits about SELinux AVC denials and certain types of security-relevant events such as system logins, account modifications, and authentication events performed by programs such as sudo. Under its default configuration, auditd has modest disk space requirements, and should not noticeably impact system performance.

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

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

type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)
  • msg=audit(1226874073.147:96)
    • The number in parentheses is the unformatted time stamp (Epoch time) for the event, which can be converted to standard time by using the date command.
  • { getattr }
    • The item in braces indicates the permission that was denied. getattr indicates the source process was trying to read the target file's status information. This occurs before reading files. This action is denied due to the file being accessed having the wrong label. Commonly seen permissions include getattr, read, and write.
  • comm="httpd"
    • The executable that launched the process. The full path of the executable is found in the exe= section of the system call (SYSCALL) message, which in this case, is exe="/usr/sbin/httpd".
  • path="/var/www/html/file1"
    • The path to the object (target) the process attempted to access.
  • scontext="unconfined_u:system_r:httpd_t:s0"
    • The SELinux context of the process that attempted the denied action. In this case, it is the SELinux context of the Apache HTTP Server, which is running in the httpd_t domain.
  • tcontext="unconfined_u:object_r:samba_share_t:s0"
    • The SELinux context of the object (target) the process attempted to access. In this case, it is the SELinux context of file1. Note: the samba_share_t type is not accessible to processes running in the httpd_t domain.
  • From the system call (SYSCALL) message, two items are of interest:
    • success=no: indicates whether the denial (AVC) was enforced or not. success=no indicates the system call was not successful (SELinux denied access). success=yes indicates the system call was successful - this can be seen for permissive domains or unconfined domains, such as initrc_t and kernel_t.
    • exe="/usr/sbin/httpd": the full path to the executable that launched the process, which in this case, is exe="/usr/sbin/httpd".
Group   Configure auditd Rules for Comprehensive Auditing   Group contains 1 group and 1 rule
[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 Information on the Use of Privileged Commands   Group contains 1 rule
[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 - 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 perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: 
-a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
Rationale:
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats.

Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_audit_rules_privileged_commands_sudo
Identifiers and References

References:  BP28(R19), 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, CCI-000130, CCI-000135, CCI-000169, CCI-000172, CCI-002884, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, FAU_GEN.1.1.c, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, OL07-00-030690, SV-221809r833067_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-OL07-00-030690
  - 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: Perform remediation of Audit rules for /usr/bin/sudo
  block:

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

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

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

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

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

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

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

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

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

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

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

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/sudo -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0

  - name: Declare list of syscalls
    set_fact:
      syscalls: []
      syscall_grouping: []

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

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

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

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

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

  - name: Add the audit rule to {{ audit_file }}
    lineinfile:
      path: '{{ audit_file }}'
      line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/sudo -F perm=x
        -F auid>=1000 -F auid!=unset -F key=privileged
      create: true
      mode: o-rwx
      state: present
    when: syscalls_found | length == 0
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-030690
  - 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


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

ACTION_ARCH_FILTERS="-a always,exit"
OTHER_FILTERS="-F path=/usr/bin/sudo -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule

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

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


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

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

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

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

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

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

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

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

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

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

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

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



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

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

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

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

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

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

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

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

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

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

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   GRUB2 bootloader configuration   Group contains 2 groups and 8 rules
[ref]   During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows for the selection of different kernels - possibly on different partitions or media. The default Oracle Linux 7 boot loader for x86 systems is called GRUB2. Options it can pass to the kernel include single-user mode, which provides root access without any authentication, and the ability to disable SELinux. To prevent local users from modifying the boot parameters and endangering security, protect the boot loader configuration with a password and ensure its configuration file's permissions are set properly.
Group   Non-UEFI GRUB2 bootloader configuration   Group contains 1 rule
[ref]   Non-UEFI GRUB2 bootloader configuration

Rule   Set Boot Loader Password in grub2   [ref]

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the password by running the following command: 
# grub2-setpassword
When prompted, enter the password that was selected.

Warning:  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Rationale:
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_password
Identifiers and References

References:  BP28(R17), 1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, OL07-00-010482, SV-221700r744071_rule

Group   UEFI GRUB2 bootloader configuration   Group contains 1 rule
[ref]   UEFI GRUB2 bootloader configuration

Rule   Set the UEFI Boot Loader Password   [ref]

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the password by running the following command: 
# grub2-setpassword
When prompted, enter the password that was selected.

Warning:  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Rationale:
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_uefi_password
Identifiers and References

References:  BP28(R17), 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, OL07-00-010491, SV-221702r744074_rule

Rule   Configure L1 Terminal Fault mitigations   [ref]

L1 Terminal Fault (L1TF) is a hardware vulnerability which allows unprivileged speculative access to data which is available in the Level 1 Data Cache when the page table entry isn't present. Select the appropriate mitigation by adding the argument l1tf=full,force to the default GRUB 2 command line for the Linux operating system. To ensure that l1tf=full,force is added as a kernel command line argument to newly installed kernels, add l1tf=full,force to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... l1tf=full,force ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="l1tf=full,force"
Since Linux Kernel 4.19 you can check the L1TF vulnerability state with the following command: cat /sys/devices/system/cpu/vulnerabilities/l1tf
Warning:  Enabling L1TF mitigations may impact performance of the system.
Rationale:
The L1TF vulnerability allows an attacker to bypass memory access security controls imposed by the system or hypervisor. The L1TF vulnerability allows read access to any physical memory location that is cached in the L1 Data Cache.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_l1tf_argument
Identifiers and References

References:  BP28(R8)


[customizations.kernel]
append = "l1tf=full,force"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_l1tf_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
- name: XCCDF Value var_l1tf_options # promote to variable
  set_fact:
    var_l1tf_options: !!str full,force
  tags:
    - always

- name: Check l1tf argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*l1tf=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_l1tf_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Replace existing l1tf argument
  replace:
    path: /etc/default/grub
    regexp: l1tf=\w+
    replace: l1tf={{ var_l1tf_options }}
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc == 0
  tags:
  - grub2_l1tf_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Add l1tf argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 l1tf={{ var_l1tf_options }}"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc != 0
  tags:
  - grub2_l1tf_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="l1tf={{ var_l1tf_options }}"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_l1tf_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

var_l1tf_options='full,force'




# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*l1tf=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an l1tf= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)l1tf=[^[:space:]]\+\(.*\"\)/\1l1tf=$var_l1tf_options\2/"  '/etc/default/grub'
else
       # no l1tf=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 l1tf=$var_l1tf_options\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=l1tf=$var_l1tf_options

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

Rule   Force kernel panic on uncorrected MCEs   [ref]

A Machine Check Exception is an error generated by the CPU itdetects an error in itself, memory or I/O devices. These errors may be corrected and generate a check log entry, if an error cannot be corrected the kernel may panic or SIGBUS. To force the kernel to panic on any uncorrected error reported by Machine Check set the MCE tolerance to zero by adding mce=0 to the default GRUB 2 command line for the Linux operating system. To ensure that mce=0 is added as a kernel command line argument to newly installed kernels, add mce=0 to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... mce=0 ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="mce=0"
Rationale:
Allowing uncorrected errors to result on a SIGBUS may allow an attacker to continue trying to exploit a vulnerability such as Rowhammer.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_mce_argument
Identifiers and References

References:  BP28(R8)


[customizations.kernel]
append = "mce=0"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_mce_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check mce argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*mce=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_mce_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Replace existing mce argument
  replace:
    path: /etc/default/grub
    regexp: mce=\w+
    replace: mce=0
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc == 0
  tags:
  - grub2_mce_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add mce argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 mce=0"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc != 0
  tags:
  - grub2_mce_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="mce=0"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_mce_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*mce=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an mce= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)mce=[^[:space:]]\+\(.*\"\)/\1mce=0\2/"  '/etc/default/grub'
else
       # no mce=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 mce=0\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=mce=0

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

Rule   Configure the confidence in TPM for entropy   [ref]

The TPM security chip that is available in most modern systems has a hardware RNG. It is also used to feed the entropy pool, but generally not credited entropy. Use rng_core.default_quality in the kernel command line to set the trust level on the hardware generators. The trust level defines the amount of entropy to credit. A value of 0 tells the system not to trust the hardware random number generators available, and doesn't credit any entropy to the pool. A value of 1000 assigns full confidence in the generators, and credits all the entropy it provides to the pool. Note that the value of rng_core.default_quality is global, affecting the trust on all hardware random number generators. Select the appropriate confidence by adding the argument rng_core.default_quality=500 to the default GRUB 2 command line for the Linux operating system. To ensure that rng_core.default_quality=500 is added as a kernel command line argument to newly installed kernels, add rng_core.default_quality=500 to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... rng_core.default_quality=500 ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="rng_core.default_quality=500"
Rationale:
A system may struggle to initialize its entropy pool and end up starving. Crediting entropy from the hardware number generators available in the system helps fill up the entropy pool.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_grub2_rng_core_default_quality_argument
Identifiers and References

References:  BP28(R8)


[customizations.kernel]
append = "rng_core.default_quality=500"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_rng_core_default_quality_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy
- name: XCCDF Value var_rng_core_default_quality # promote to variable
  set_fact:
    var_rng_core_default_quality: !!str 500
  tags:
    - always

- name: Check rng_core.default_quality argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*rng_core.default_quality=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_rng_core_default_quality_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Replace existing rng_core.default_quality argument
  replace:
    path: /etc/default/grub
    regexp: rng_core.default_quality=\w+
    replace: rng_core.default_quality={{ var_rng_core_default_quality }}
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc == 0
  tags:
  - grub2_rng_core_default_quality_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Add rng_core.default_quality argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 rng_core.default_quality={{ var_rng_core_default_quality }}"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc != 0
  tags:
  - grub2_rng_core_default_quality_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="rng_core.default_quality={{ var_rng_core_default_quality
    }}"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_rng_core_default_quality_argument
  - low_disruption
  - low_severity
  - medium_complexity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

var_rng_core_default_quality='500'




# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*rng_core.default_quality=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an rng_core.default_quality= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)rng_core.default_quality=[^[:space:]]\+\(.*\"\)/\1rng_core.default_quality=$var_rng_core_default_quality\2/"  '/etc/default/grub'
else
       # no rng_core.default_quality=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 rng_core.default_quality=$var_rng_core_default_quality\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=rng_core.default_quality=$var_rng_core_default_quality

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

Rule   Disable merging of slabs with similar size   [ref]

The kernel may merge similar slabs together to reduce overhead and increase cache hotness of objects. Disabling merging of slabs keeps the slabs separate and reduces the risk of kernel heap overflows overwriting objects in merged caches. To disable merging of slabs in the Kernel add the argument slab_nomerge=yes to the default GRUB 2 command line for the Linux operating system. To ensure that slab_nomerge=yes is added as a kernel command line argument to newly installed kernels, add slab_nomerge=yes to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... slab_nomerge=yes ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="slab_nomerge=yes"
Warning:  Disabling merge of slabs will slightly increase kernel memory utilization.
Rationale:
Disabling the merge of slabs of similar sizes prevents the kernel from merging a seemingly useless but vulnerable slab with a useful and valuable slab. This increase the risk that a heap overflow could overwrite objects from merged caches, with unmerged caches the heap overflow would only affect the objects in the same cache. Overall, this reduces the kernel attack surface area by isolating slabs from each other.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_slab_nomerge_argument
Identifiers and References

References:  BP28(R8)


[customizations.kernel]
append = "slab_nomerge=yes"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_slab_nomerge_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check slab_nomerge argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*slab_nomerge=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_slab_nomerge_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Replace existing slab_nomerge argument
  replace:
    path: /etc/default/grub
    regexp: slab_nomerge=\w+
    replace: slab_nomerge=yes
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc == 0
  tags:
  - grub2_slab_nomerge_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add slab_nomerge argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 slab_nomerge=yes"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc != 0
  tags:
  - grub2_slab_nomerge_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="slab_nomerge=yes"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_slab_nomerge_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*slab_nomerge=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an slab_nomerge= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)slab_nomerge=[^[:space:]]\+\(.*\"\)/\1slab_nomerge=yes\2/"  '/etc/default/grub'
else
       # no slab_nomerge=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 slab_nomerge=yes\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=slab_nomerge=yes

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

Rule   Configure Speculative Store Bypass Mitigation   [ref]

Certain CPUs are vulnerable to an exploit against a common wide industry wide performance optimization known as Speculative Store Bypass (SSB). In such cases, recent stores to the same memory location cannot always be observed by later loads during speculative execution. However, such stores are unlikely and thus they can be detected prior to instruction retirement at the end of a particular speculation execution window. Since Linux Kernel 4.17 you can check the SSB mitigation state with the following command: cat /sys/devices/system/cpu/vulnerabilities/spec_store_bypass Select the appropriate SSB state by adding the argument spec_store_bypass_disable=seccomp to the default GRUB 2 command line for the Linux operating system. To ensure that spec_store_bypass_disable=seccomp is added as a kernel command line argument to newly installed kernels, add spec_store_bypass_disable=seccomp to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... spec_store_bypass_disable=seccomp ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="spec_store_bypass_disable=seccomp"
Warning:  Disabling Speculative Store Bypass may impact performance of the system.
Rationale:
In vulnerable processsors, the speculatively forwarded store can be used in a cache side channel attack. An example of this is reading memory to which the attacker does not directly have access, for example inside the sandboxed code.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_spec_store_bypass_disable_argument
Identifiers and References

References:  BP28(R8)


[customizations.kernel]
append = "spec_store_bypass_disable=seccomp"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_spec_store_bypass_disable_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy
- name: XCCDF Value var_spec_store_bypass_disable_options # promote to variable
  set_fact:
    var_spec_store_bypass_disable_options: !!str seccomp
  tags:
    - always

- name: Check spec_store_bypass_disable argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*spec_store_bypass_disable=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_spec_store_bypass_disable_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Replace existing spec_store_bypass_disable argument
  replace:
    path: /etc/default/grub
    regexp: spec_store_bypass_disable=\w+
    replace: spec_store_bypass_disable={{ var_spec_store_bypass_disable_options }}
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc == 0
  tags:
  - grub2_spec_store_bypass_disable_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add spec_store_bypass_disable argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 spec_store_bypass_disable={{ var_spec_store_bypass_disable_options
      }}"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc != 0
  tags:
  - grub2_spec_store_bypass_disable_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="spec_store_bypass_disable={{ var_spec_store_bypass_disable_options
    }}"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_spec_store_bypass_disable_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

var_spec_store_bypass_disable_options='seccomp'




# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*spec_store_bypass_disable=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an spec_store_bypass_disable= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)spec_store_bypass_disable=[^[:space:]]\+\(.*\"\)/\1spec_store_bypass_disable=$var_spec_store_bypass_disable_options\2/"  '/etc/default/grub'
else
       # no spec_store_bypass_disable=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 spec_store_bypass_disable=$var_spec_store_bypass_disable_options\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=spec_store_bypass_disable=$var_spec_store_bypass_disable_options

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

Rule   Enforce Spectre v2 mitigation   [ref]

Spectre V2 is an indirect branch poisoning attack that can lead to data leakage. An exploit for Spectre V2 tricks the indirect branch predictor into executing code from a future indirect branch chosen by the attacker, even if the privilege level is different. Since Linux Kernel 4.15 you can check the Spectre V2 mitigation state with the following command: cat /sys/devices/system/cpu/vulnerabilities/spectre_v2 Enforce the Spectre V2 mitigation by adding the argument spectre_v2=on to the default GRUB 2 command line for the Linux operating system. To ensure that spectre_v2=on) is added as a kernel command line argument to newly installed kernels, add spectre_v2=on) to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... spectre_v2=on) ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="spectre_v2=on)"
Rationale:
The Spectre V2 vulnerability allows an attacker to read memory that he should not have access to.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_grub2_spectre_v2_argument
Identifiers and References

References:  BP28(R8)


[customizations.kernel]
append = "spectre_v2=on"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_spectre_v2_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Check spectre_v2 argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*spectre_v2=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_spectre_v2_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Replace existing spectre_v2 argument
  replace:
    path: /etc/default/grub
    regexp: spectre_v2=\w+
    replace: spectre_v2=on
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc == 0
  tags:
  - grub2_spectre_v2_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Add spectre_v2 argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 spectre_v2=on"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck.rc != 0
  tags:
  - grub2_spectre_v2_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="spectre_v2=on"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_spectre_v2_argument
  - high_severity
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if rpm --quiet -q grub2-common && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*spectre_v2=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an spectre_v2= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)spectre_v2=[^[:space:]]\+\(.*\"\)/\1spectre_v2=on\2/"  '/etc/default/grub'
else
       # no spectre_v2=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 spectre_v2=on\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=spectre_v2=on

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Configuration and Firewalls   Group contains 5 groups and 37 rules
[ref]   Most systems must be connected to a network of some sort, and this brings with it the substantial risk of network attack. This section discusses the security impact of decisions about networking which must be made when configuring a system.

This section also discusses firewalls, network access controls, and other network security frameworks, which allow system-level rules to be written that can limit an attackers' ability to connect to your system. These rules can specify that network traffic should be allowed or denied from certain IP addresses, hosts, and networks. The rules can also specify which of the system's network services are available to particular hosts or networks.
Group   IPv6   Group contains 1 group and 16 rules
[ref]   The system includes support for Internet Protocol version 6. A major and often-mentioned improvement over IPv4 is its enormous increase in the number of available addresses. Another important feature is its support for automatic configuration of many network settings.
Group   Configure IPv6 Settings if Necessary   Group contains 16 rules
[ref]   A major feature of IPv6 is the extent to which systems implementing it can automatically configure their networking devices using information from the network. From a security perspective, manually configuring important configuration information is preferable to accepting it from the network in an unauthenticated fashion.

Rule   Configure Accepting Default Router in Router Advertisements on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_ra_defrtr kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.accept_ra_defrtr=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.accept_ra_defrtr = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra_defrtr
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_ra_defrtr.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_defrtr
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.all.accept_ra_defrtr from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_ra_defrtr
    replace: '#net.ipv6.conf.all.accept_ra_defrtr'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_defrtr
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_ra_defrtr_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_ra_defrtr_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_ra_defrtr is set
  sysctl:
    name: net.ipv6.conf.all.accept_ra_defrtr
    value: '{{ sysctl_net_ipv6_conf_all_accept_ra_defrtr_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_defrtr
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.all.accept_ra_defrtr from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_ra_defrtr.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_ra_defrtr" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_ra_defrtr_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_ra_defrtr
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_ra_defrtr="$sysctl_net_ipv6_conf_all_accept_ra_defrtr_value"

#
# If net.ipv6.conf.all.accept_ra_defrtr present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_ra_defrtr = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_ra_defrtr")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_ra_defrtr_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_ra_defrtr\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_ra_defrtr\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Accepting Prefix Information in Router Advertisements on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_ra_pinfo kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.accept_ra_pinfo=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.accept_ra_pinfo = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra_pinfo
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_ra_pinfo.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_pinfo
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.all.accept_ra_pinfo from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_ra_pinfo
    replace: '#net.ipv6.conf.all.accept_ra_pinfo'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_pinfo
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_ra_pinfo_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_ra_pinfo_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_ra_pinfo is set
  sysctl:
    name: net.ipv6.conf.all.accept_ra_pinfo
    value: '{{ sysctl_net_ipv6_conf_all_accept_ra_pinfo_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_pinfo
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.all.accept_ra_pinfo from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_ra_pinfo.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_ra_pinfo" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_ra_pinfo_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_ra_pinfo
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_ra_pinfo="$sysctl_net_ipv6_conf_all_accept_ra_pinfo_value"

#
# If net.ipv6.conf.all.accept_ra_pinfo present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_ra_pinfo = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_ra_pinfo")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_ra_pinfo_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_ra_pinfo\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_ra_pinfo\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Accepting Router Preference in Router Advertisements on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_ra_rtr_pref kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.accept_ra_rtr_pref=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.accept_ra_rtr_pref = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra_rtr_pref
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_ra_rtr_pref.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_rtr_pref
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.all.accept_ra_rtr_pref from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_ra_rtr_pref
    replace: '#net.ipv6.conf.all.accept_ra_rtr_pref'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_rtr_pref
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_ra_rtr_pref_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_ra_rtr_pref_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_ra_rtr_pref is set
  sysctl:
    name: net.ipv6.conf.all.accept_ra_rtr_pref
    value: '{{ sysctl_net_ipv6_conf_all_accept_ra_rtr_pref_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_ra_rtr_pref
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.all.accept_ra_rtr_pref from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_ra_rtr_pref.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_ra_rtr_pref" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_ra_rtr_pref_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_ra_rtr_pref
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_ra_rtr_pref="$sysctl_net_ipv6_conf_all_accept_ra_rtr_pref_value"

#
# If net.ipv6.conf.all.accept_ra_rtr_pref present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_ra_rtr_pref = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_ra_rtr_pref")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_ra_rtr_pref_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_ra_rtr_pref\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_ra_rtr_pref\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Accepting ICMP Redirects for All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.accept_redirects = 0
Rationale:
An illicit ICMP redirect message could result in a man-in-the-middle attack.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_redirects
Identifiers and References

References:  BP28(R22), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_redirects

- name: Comment out any occurrences of net.ipv6.conf.all.accept_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_redirects
    replace: '#net.ipv6.conf.all.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_redirects
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_redirects is set
  sysctl:
    name: net.ipv6.conf.all.accept_redirects
    value: '{{ sysctl_net_ipv6_conf_all_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_redirects

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

# Comment out any occurrences of net.ipv6.conf.all.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_redirects_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_redirects="$sysctl_net_ipv6_conf_all_accept_redirects_value"

#
# If net.ipv6.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.accept_source_route kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-040830, SV-221894r880666_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040830
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_source_route

- name: Comment out any occurrences of net.ipv6.conf.all.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.accept_source_route
    replace: '#net.ipv6.conf.all.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040830
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.all.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_all_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040830
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_all_accept_source_route

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

# Comment out any occurrences of net.ipv6.conf.all.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_accept_source_route_value='0'


#
# Set runtime for net.ipv6.conf.all.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_source_route="$sysctl_net_ipv6_conf_all_accept_source_route_value"

#
# If net.ipv6.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Auto Configuration on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.autoconf kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.autoconf=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.autoconf = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_autoconf
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.autoconf.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_autoconf
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.all.autoconf from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.autoconf
    replace: '#net.ipv6.conf.all.autoconf'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_autoconf
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_all_autoconf_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_autoconf_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.autoconf is set
  sysctl:
    name: net.ipv6.conf.all.autoconf
    value: '{{ sysctl_net_ipv6_conf_all_autoconf_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_autoconf
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.all.autoconf from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.autoconf.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.autoconf" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_autoconf_value='0'


#
# Set runtime for net.ipv6.conf.all.autoconf
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.autoconf="$sysctl_net_ipv6_conf_all_autoconf_value"

#
# If net.ipv6.conf.all.autoconf present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.autoconf = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.autoconf")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_autoconf_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.autoconf\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.autoconf\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Maximum Number of Autoconfigured Addresses on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.max_addresses kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.max_addresses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.max_addresses = 1
Rationale:
The number of global unicast IPv6 addresses for each interface should be limited exactly to the number of statically configured addresses.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_max_addresses
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.max_addresses.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_max_addresses
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.all.max_addresses from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.max_addresses
    replace: '#net.ipv6.conf.all.max_addresses'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_max_addresses
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_all_max_addresses_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_max_addresses_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.max_addresses is set
  sysctl:
    name: net.ipv6.conf.all.max_addresses
    value: '{{ sysctl_net_ipv6_conf_all_max_addresses_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_max_addresses
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.all.max_addresses from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.max_addresses.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.max_addresses" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_max_addresses_value='1'


#
# Set runtime for net.ipv6.conf.all.max_addresses
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.max_addresses="$sysctl_net_ipv6_conf_all_max_addresses_value"

#
# If net.ipv6.conf.all.max_addresses present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.max_addresses = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.max_addresses")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_max_addresses_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.max_addresses\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.max_addresses\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Denying Router Solicitations on All IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.all.router_solicitations kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.all.router_solicitations=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.all.router_solicitations = 0
Rationale:
To prevent discovery of the system by other systems, router solicitation requests should be denied.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_router_solicitations
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.all.router_solicitations.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_router_solicitations
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.all.router_solicitations from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.all.router_solicitations
    replace: '#net.ipv6.conf.all.router_solicitations'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_router_solicitations
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_all_router_solicitations_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_all_router_solicitations_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.all.router_solicitations is set
  sysctl:
    name: net.ipv6.conf.all.router_solicitations
    value: '{{ sysctl_net_ipv6_conf_all_router_solicitations_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_all_router_solicitations
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.all.router_solicitations from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.router_solicitations.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.all.router_solicitations" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_all_router_solicitations_value='0'


#
# Set runtime for net.ipv6.conf.all.router_solicitations
#
/sbin/sysctl -q -n -w net.ipv6.conf.all.router_solicitations="$sysctl_net_ipv6_conf_all_router_solicitations_value"

#
# If net.ipv6.conf.all.router_solicitations present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.all.router_solicitations = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.router_solicitations")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_router_solicitations_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.router_solicitations\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.router_solicitations\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Accepting Default Router in Router Advertisements on All IPv6 Interfaces By Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_ra_defrtr kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.accept_ra_defrtr=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.accept_ra_defrtr = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra_defrtr
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_ra_defrtr.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_defrtr
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.default.accept_ra_defrtr from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_ra_defrtr
    replace: '#net.ipv6.conf.default.accept_ra_defrtr'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_defrtr
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_ra_defrtr_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_ra_defrtr_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_ra_defrtr is set
  sysctl:
    name: net.ipv6.conf.default.accept_ra_defrtr
    value: '{{ sysctl_net_ipv6_conf_default_accept_ra_defrtr_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_defrtr
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.default.accept_ra_defrtr from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_ra_defrtr.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_ra_defrtr" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_ra_defrtr_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_ra_defrtr
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_ra_defrtr="$sysctl_net_ipv6_conf_default_accept_ra_defrtr_value"

#
# If net.ipv6.conf.default.accept_ra_defrtr present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_ra_defrtr = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_ra_defrtr")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_ra_defrtr_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_ra_defrtr\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_ra_defrtr\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Accepting Prefix Information in Router Advertisements on All IPv6 Interfaces By Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_ra_pinfo kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.accept_ra_pinfo=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.accept_ra_pinfo = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra_pinfo
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_ra_pinfo.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_pinfo
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.default.accept_ra_pinfo from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_ra_pinfo
    replace: '#net.ipv6.conf.default.accept_ra_pinfo'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_pinfo
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_ra_pinfo_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_ra_pinfo_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_ra_pinfo is set
  sysctl:
    name: net.ipv6.conf.default.accept_ra_pinfo
    value: '{{ sysctl_net_ipv6_conf_default_accept_ra_pinfo_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_pinfo
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.default.accept_ra_pinfo from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_ra_pinfo.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_ra_pinfo" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_ra_pinfo_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_ra_pinfo
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_ra_pinfo="$sysctl_net_ipv6_conf_default_accept_ra_pinfo_value"

#
# If net.ipv6.conf.default.accept_ra_pinfo present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_ra_pinfo = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_ra_pinfo")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_ra_pinfo_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_ra_pinfo\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_ra_pinfo\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Accepting Router Preference in Router Advertisements on All IPv6 Interfaces By Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_ra_rtr_pref kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.accept_ra_rtr_pref=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.accept_ra_rtr_pref = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra_rtr_pref
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_ra_rtr_pref.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_rtr_pref
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.default.accept_ra_rtr_pref from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_ra_rtr_pref
    replace: '#net.ipv6.conf.default.accept_ra_rtr_pref'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_rtr_pref
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_ra_rtr_pref_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_ra_rtr_pref_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_ra_rtr_pref is set
  sysctl:
    name: net.ipv6.conf.default.accept_ra_rtr_pref
    value: '{{ sysctl_net_ipv6_conf_default_accept_ra_rtr_pref_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_ra_rtr_pref
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.default.accept_ra_rtr_pref from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_ra_rtr_pref.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_ra_rtr_pref" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_ra_rtr_pref_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_ra_rtr_pref
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_ra_rtr_pref="$sysctl_net_ipv6_conf_default_accept_ra_rtr_pref_value"

#
# If net.ipv6.conf.default.accept_ra_rtr_pref present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_ra_rtr_pref = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_ra_rtr_pref")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_ra_rtr_pref_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_ra_rtr_pref\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_ra_rtr_pref\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.accept_redirects = 0
Rationale:
An illicit ICMP redirect message could result in a man-in-the-middle attack.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_redirects
Identifiers and References

References:  BP28(R22), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_redirects

- name: Comment out any occurrences of net.ipv6.conf.default.accept_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_redirects
    replace: '#net.ipv6.conf.default.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv6.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv6_conf_default_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_redirects

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

# Comment out any occurrences of net.ipv6.conf.default.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_redirects_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_redirects="$sysctl_net_ipv6_conf_default_accept_redirects_value"

#
# If net.ipv6.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default   [ref]

To set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route

- name: Comment out any occurrences of net.ipv6.conf.default.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.accept_source_route
    replace: '#net.ipv6.conf.default.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv6.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv6_conf_default_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(b)
  - NIST-800-53-CM-6.1(iv)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv6_conf_default_accept_source_route

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

# Comment out any occurrences of net.ipv6.conf.default.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_accept_source_route_value='0'


#
# Set runtime for net.ipv6.conf.default.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_source_route="$sysctl_net_ipv6_conf_default_accept_source_route_value"

#
# If net.ipv6.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Auto Configuration on All IPv6 Interfaces By Default   [ref]

To set the runtime status of the net.ipv6.conf.default.autoconf kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.autoconf=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.autoconf = 0
Rationale:
An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_autoconf
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.autoconf.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_autoconf
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.default.autoconf from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.autoconf
    replace: '#net.ipv6.conf.default.autoconf'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_autoconf
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_default_autoconf_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_autoconf_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.autoconf is set
  sysctl:
    name: net.ipv6.conf.default.autoconf
    value: '{{ sysctl_net_ipv6_conf_default_autoconf_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_autoconf
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.default.autoconf from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.autoconf.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.autoconf" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_autoconf_value='0'


#
# Set runtime for net.ipv6.conf.default.autoconf
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.autoconf="$sysctl_net_ipv6_conf_default_autoconf_value"

#
# If net.ipv6.conf.default.autoconf present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.autoconf = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.autoconf")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_autoconf_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.autoconf\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.autoconf\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Maximum Number of Autoconfigured Addresses on All IPv6 Interfaces By Default   [ref]

To set the runtime status of the net.ipv6.conf.default.max_addresses kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.max_addresses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.max_addresses = 1
Rationale:
The number of global unicast IPv6 addresses for each interface should be limited exactly to the number of statically configured addresses.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_max_addresses
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.max_addresses.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_max_addresses
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.default.max_addresses from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.max_addresses
    replace: '#net.ipv6.conf.default.max_addresses'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_max_addresses
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_default_max_addresses_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_max_addresses_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.max_addresses is set
  sysctl:
    name: net.ipv6.conf.default.max_addresses
    value: '{{ sysctl_net_ipv6_conf_default_max_addresses_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_max_addresses
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.default.max_addresses from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.max_addresses.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.max_addresses" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_max_addresses_value='1'


#
# Set runtime for net.ipv6.conf.default.max_addresses
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.max_addresses="$sysctl_net_ipv6_conf_default_max_addresses_value"

#
# If net.ipv6.conf.default.max_addresses present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.max_addresses = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.max_addresses")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_max_addresses_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.max_addresses\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.max_addresses\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Denying Router Solicitations on All IPv6 Interfaces By Default   [ref]

To set the runtime status of the net.ipv6.conf.default.router_solicitations kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv6.conf.default.router_solicitations=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv6.conf.default.router_solicitations = 0
Rationale:
To prevent discovery of the system by other systems, router solicitation requests should be denied.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_router_solicitations
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv6.conf.default.router_solicitations.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_router_solicitations
  - unknown_severity

- name: Comment out any occurrences of net.ipv6.conf.default.router_solicitations
    from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv6.conf.default.router_solicitations
    replace: '#net.ipv6.conf.default.router_solicitations'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_router_solicitations
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv6_conf_default_router_solicitations_value # promote to variable
  set_fact:
    sysctl_net_ipv6_conf_default_router_solicitations_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv6.conf.default.router_solicitations is set
  sysctl:
    name: net.ipv6.conf.default.router_solicitations
    value: '{{ sysctl_net_ipv6_conf_default_router_solicitations_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv6_conf_default_router_solicitations
  - unknown_severity

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

# Comment out any occurrences of net.ipv6.conf.default.router_solicitations from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.router_solicitations.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv6.conf.default.router_solicitations" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv6_conf_default_router_solicitations_value='0'


#
# Set runtime for net.ipv6.conf.default.router_solicitations
#
/sbin/sysctl -q -n -w net.ipv6.conf.default.router_solicitations="$sysctl_net_ipv6_conf_default_router_solicitations_value"

#
# If net.ipv6.conf.default.router_solicitations present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv6.conf.default.router_solicitations = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.router_solicitations")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_router_solicitations_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.router_solicitations\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.router_solicitations\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Kernel Parameters Which Affect Networking   Group contains 2 groups and 21 rules
[ref]   The sysctl utility is used to set parameters which affect the operation of the Linux kernel. Kernel parameters which affect networking and have security implications are described here.
Group   Network Related Kernel Runtime Parameters for Hosts and Routers   Group contains 18 rules
[ref]   Certain kernel parameters should be set for systems which are acting as either hosts or routers to improve the system's ability defend against certain types of IPv4 protocol attacks.

Rule   Disable Accepting Packets Routed Between Local Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_local kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.accept_local=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.accept_local = 0
Rationale:
Configure net.ipv4.conf.all.accept_local=0 to consider as invalid the packets received from outside whose source is the 127.0.0.0/8 address block. In combination with suitable routing, this can be used to direct packets between two local interfaces over the wire and have them accepted properly.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_local
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.accept_local.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_local

- name: Comment out any occurrences of net.ipv4.conf.all.accept_local from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.accept_local
    replace: '#net.ipv4.conf.all.accept_local'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_local

- name: Ensure sysctl net.ipv4.conf.all.accept_local is set to 0
  sysctl:
    name: net.ipv4.conf.all.accept_local
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_local

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

# Comment out any occurrences of net.ipv4.conf.all.accept_local from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_local.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.accept_local" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.conf.all.accept_local
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_local="0"

#
# If net.ipv4.conf.all.accept_local present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.accept_local = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_local")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_local\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_local\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Accepting ICMP Redirects for All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.accept_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required."
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, 5.10.1.1, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000366, CCI-001503, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, OL07-00-040641, SV-221879r880654_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040641
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.accept_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.accept_redirects
    replace: '#net.ipv4.conf.all.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040641
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.all.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_all_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040641
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_redirects

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

# Comment out any occurrences of net.ipv4.conf.all.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_accept_redirects_value='0'


#
# Set runtime for net.ipv4.conf.all.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_redirects="$sysctl_net_ipv4_conf_all_accept_redirects_value"

#
# If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-040610, SV-221873r880636_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040610
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_source_route

- name: Comment out any occurrences of net.ipv4.conf.all.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.accept_source_route
    replace: '#net.ipv4.conf.all.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040610
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_source_route
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.accept_source_route is set
  sysctl:
    name: net.ipv4.conf.all.accept_source_route
    value: '{{ sysctl_net_ipv4_conf_all_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040610
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_accept_source_route

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

# Comment out any occurrences of net.ipv4.conf.all.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_accept_source_route_value='0'


#
# Set runtime for net.ipv4.conf.all.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_source_route="$sysctl_net_ipv4_conf_all_accept_source_route_value"

#
# If net.ipv4.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure ARP filtering for All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.arp_filter kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.arp_filter=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.arp_filter = 0
Warning:  This behaviour may cause problems to system on a high availability or load balancing configuration.
Rationale:
Prevents the Linux Kernel from handling the ARP table globally. By default, the kernel may respond to an ARP request from a certain interface with information from another interface.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_arp_filter
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.arp_filter.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_arp_filter

- name: Comment out any occurrences of net.ipv4.conf.all.arp_filter from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.arp_filter
    replace: '#net.ipv4.conf.all.arp_filter'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_arp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_all_arp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_arp_filter_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.arp_filter is set
  sysctl:
    name: net.ipv4.conf.all.arp_filter
    value: '{{ sysctl_net_ipv4_conf_all_arp_filter_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_arp_filter

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

# Comment out any occurrences of net.ipv4.conf.all.arp_filter from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.arp_filter.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.arp_filter" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_arp_filter_value='0'


#
# Set runtime for net.ipv4.conf.all.arp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.arp_filter="$sysctl_net_ipv4_conf_all_arp_filter_value"

#
# If net.ipv4.conf.all.arp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.arp_filter = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.arp_filter")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_arp_filter_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.arp_filter\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.arp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Response Mode of ARP Requests for All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.arp_ignore kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.arp_ignore=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.arp_ignore = 2
Warning:  The ARP response mode may impact behaviour of workloads and firewalls on the system.
Rationale:
Avoids ARP Flux on system that have more than one interface on the same subnet.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_arp_ignore
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.arp_ignore.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_arp_ignore

- name: Comment out any occurrences of net.ipv4.conf.all.arp_ignore from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.arp_ignore
    replace: '#net.ipv4.conf.all.arp_ignore'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_arp_ignore
- name: XCCDF Value sysctl_net_ipv4_conf_all_arp_ignore_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_arp_ignore_value: !!str 2
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.arp_ignore is set
  sysctl:
    name: net.ipv4.conf.all.arp_ignore
    value: '{{ sysctl_net_ipv4_conf_all_arp_ignore_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_arp_ignore

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

# Comment out any occurrences of net.ipv4.conf.all.arp_ignore from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.arp_ignore.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.arp_ignore" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_arp_ignore_value='2'


#
# Set runtime for net.ipv4.conf.all.arp_ignore
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.arp_ignore="$sysctl_net_ipv4_conf_all_arp_ignore_value"

#
# If net.ipv4.conf.all.arp_ignore present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.arp_ignore = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.arp_ignore")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_arp_ignore_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.arp_ignore\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.arp_ignore\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.route_localnet kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.route_localnet=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.route_localnet = 0
Rationale:
Refuse the routing of packets whose source or destination address is the local loopback. This prohibits the use of network 127/8 for local routing purposes. Enabling route_localnet can expose applications listening on localhost to external traffic.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_route_localnet
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.route_localnet.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_route_localnet

- name: Comment out any occurrences of net.ipv4.conf.all.route_localnet from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.route_localnet
    replace: '#net.ipv4.conf.all.route_localnet'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_route_localnet

- name: Ensure sysctl net.ipv4.conf.all.route_localnet is set to 0
  sysctl:
    name: net.ipv4.conf.all.route_localnet
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_route_localnet

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

# Comment out any occurrences of net.ipv4.conf.all.route_localnet from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.route_localnet.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.route_localnet" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.conf.all.route_localnet
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.route_localnet="0"

#
# If net.ipv4.conf.all.route_localnet present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.route_localnet = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.route_localnet")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.route_localnet\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.route_localnet\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.rp_filter = 1
Rationale:
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, OL07-00-040611, SV-221874r880639_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.rp_filter.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040611
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter

- name: Comment out any occurrences of net.ipv4.conf.all.rp_filter from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.rp_filter
    replace: '#net.ipv4.conf.all.rp_filter'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040611
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_all_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.rp_filter is set
  sysctl:
    name: net.ipv4.conf.all.rp_filter
    value: '{{ sysctl_net_ipv4_conf_all_rp_filter_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040611
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_rp_filter

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

# Comment out any occurrences of net.ipv4.conf.all.rp_filter from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.rp_filter.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.rp_filter" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_rp_filter_value='1'


#
# Set runtime for net.ipv4.conf.all.rp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.rp_filter="$sysctl_net_ipv4_conf_all_rp_filter_value"

#
# If net.ipv4.conf.all.rp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.rp_filter = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.rp_filter")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_rp_filter_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.rp_filter\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.rp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.secure_redirects = 0
Rationale:
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001503, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.secure_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.secure_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.secure_redirects
    replace: '#net.ipv4.conf.all.secure_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.all.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_all_secure_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_secure_redirects

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

# Comment out any occurrences of net.ipv4.conf.all.secure_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.secure_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.secure_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_secure_redirects_value='0'


#
# Set runtime for net.ipv4.conf.all.secure_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.secure_redirects="$sysctl_net_ipv4_conf_all_secure_redirects_value"

#
# If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.secure_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.secure_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_secure_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Sending and Accepting Shared Media Redirects for All IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.shared_media kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.shared_media=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.shared_media = 0
Rationale:
This setting should be aligned with net.ipv4.conf.all.secure_redirects because it overrides it. If shared_media is enabled for an interface secure_redirects will be enabled too.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_shared_media
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.shared_media.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_shared_media

- name: Comment out any occurrences of net.ipv4.conf.all.shared_media from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.shared_media
    replace: '#net.ipv4.conf.all.shared_media'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_shared_media
- name: XCCDF Value sysctl_net_ipv4_conf_all_shared_media_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_all_shared_media_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.all.shared_media is set
  sysctl:
    name: net.ipv4.conf.all.shared_media
    value: '{{ sysctl_net_ipv4_conf_all_shared_media_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_shared_media

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

# Comment out any occurrences of net.ipv4.conf.all.shared_media from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.shared_media.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.shared_media" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_all_shared_media_value='0'


#
# Set runtime for net.ipv4.conf.all.shared_media
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.shared_media="$sysctl_net_ipv4_conf_all_shared_media_value"

#
# If net.ipv4.conf.all.shared_media present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.all.shared_media = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.shared_media")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_shared_media_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.shared_media\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.shared_media\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.default.accept_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, OL07-00-040640, SV-221878r880651_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.accept_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040640
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.accept_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.accept_redirects
    replace: '#net.ipv4.conf.default.accept_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040640
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_redirects is set
  sysctl:
    name: net.ipv4.conf.default.accept_redirects
    value: '{{ sysctl_net_ipv4_conf_default_accept_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040640
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_redirects

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

# Comment out any occurrences of net.ipv4.conf.default.accept_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.accept_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_accept_redirects_value='0'


#
# Set runtime for net.ipv4.conf.default.accept_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_redirects="$sysctl_net_ipv4_conf_default_accept_redirects_value"

#
# If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.accept_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.default.accept_source_route = 0
Rationale:
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures.
Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_source_route
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-040620, SV-221876r880645_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.accept_source_route.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040620
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_source_route

- name: Comment out any occurrences of net.ipv4.conf.default.accept_source_route from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.accept_source_route
    replace: '#net.ipv4.conf.default.accept_source_route'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040620
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_source_route_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_accept_source_route_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.accept_source_route is set
  sysctl:
    name: net.ipv4.conf.default.accept_source_route
    value: '{{ sysctl_net_ipv4_conf_default_accept_source_route_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040620
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_accept_source_route

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

# Comment out any occurrences of net.ipv4.conf.default.accept_source_route from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_source_route.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.accept_source_route" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_accept_source_route_value='0'


#
# Set runtime for net.ipv4.conf.default.accept_source_route
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_source_route="$sysctl_net_ipv4_conf_default_accept_source_route_value"

#
# If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.accept_source_route = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_source_route")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_source_route_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.rp_filter kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.default.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.default.rp_filter = 1
Rationale:
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_rp_filter
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-040612, SV-221875r880642_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.rp_filter.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040612
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_rp_filter

- name: Comment out any occurrences of net.ipv4.conf.default.rp_filter from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.rp_filter
    replace: '#net.ipv4.conf.default.rp_filter'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040612
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_default_rp_filter_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_rp_filter_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.rp_filter is set
  sysctl:
    name: net.ipv4.conf.default.rp_filter
    value: '{{ sysctl_net_ipv4_conf_default_rp_filter_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040612
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_rp_filter

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

# Comment out any occurrences of net.ipv4.conf.default.rp_filter from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.rp_filter.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.rp_filter" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_rp_filter_value='1'


#
# Set runtime for net.ipv4.conf.default.rp_filter
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.rp_filter="$sysctl_net_ipv4_conf_default_rp_filter_value"

#
# If net.ipv4.conf.default.rp_filter present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.rp_filter = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.rp_filter")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_rp_filter_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.rp_filter\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.rp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Kernel Parameter for Accepting Secure Redirects By Default   [ref]

To set the runtime status of the net.ipv4.conf.default.secure_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.default.secure_redirects = 0
Rationale:
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_secure_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.secure_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_secure_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.secure_redirects from
    config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.secure_redirects
    replace: '#net.ipv4.conf.default.secure_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_secure_redirects_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_secure_redirects_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.secure_redirects is set
  sysctl:
    name: net.ipv4.conf.default.secure_redirects
    value: '{{ sysctl_net_ipv4_conf_default_secure_redirects_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_secure_redirects

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

# Comment out any occurrences of net.ipv4.conf.default.secure_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.secure_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.secure_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_secure_redirects_value='0'


#
# Set runtime for net.ipv4.conf.default.secure_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.secure_redirects="$sysctl_net_ipv4_conf_default_secure_redirects_value"

#
# If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.secure_redirects = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.secure_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_secure_redirects_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Configure Sending and Accepting Shared Media Redirects by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.shared_media kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.default.shared_media=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.default.shared_media = 0
Rationale:
This setting should be aligned with net.ipv4.conf.default.secure_redirects because it overrides it. If shared_media is enabled for an interface secure_redirects will be enabled too.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_shared_media
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.shared_media.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_shared_media

- name: Comment out any occurrences of net.ipv4.conf.default.shared_media from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.shared_media
    replace: '#net.ipv4.conf.default.shared_media'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_shared_media
- name: XCCDF Value sysctl_net_ipv4_conf_default_shared_media_value # promote to variable
  set_fact:
    sysctl_net_ipv4_conf_default_shared_media_value: !!str 0
  tags:
    - always

- name: Ensure sysctl net.ipv4.conf.default.shared_media is set
  sysctl:
    name: net.ipv4.conf.default.shared_media
    value: '{{ sysctl_net_ipv4_conf_default_shared_media_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_shared_media

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

# Comment out any occurrences of net.ipv4.conf.default.shared_media from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.shared_media.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.shared_media" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_conf_default_shared_media_value='0'


#
# Set runtime for net.ipv4.conf.default.shared_media
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.shared_media="$sysctl_net_ipv4_conf_default_shared_media_value"

#
# If net.ipv4.conf.default.shared_media present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.conf.default.shared_media = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.shared_media")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_shared_media_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.shared_media\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.shared_media\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.icmp_ignore_bogus_error_responses = 1
Rationale:
Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, Req-1.4.3, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity

- name: Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses
    from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses
    replace: '#net.ipv4.icmp_ignore_bogus_error_responses'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity
- name: XCCDF Value sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value # promote to variable
  set_fact:
    sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.icmp_ignore_bogus_error_responses is set
  sysctl:
    name: net.ipv4.icmp_ignore_bogus_error_responses
    value: '{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - PCI-DSS-Req-1.4.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - reboot_required
  - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
  - unknown_severity

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

# Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.icmp_ignore_bogus_error_responses" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value='1'


#
# Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
#
/sbin/sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses="$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"

#
# If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.icmp_ignore_bogus_error_responses = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_ignore_bogus_error_responses")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_ignore_bogus_error_responses\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_ignore_bogus_error_responses\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Set Kernel Parameter to Increase Local Port Range   [ref]

To set the runtime status of the net.ipv4.ip_local_port_range kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.ip_local_port_range=32768 65535
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.ip_local_port_range = 32768 65535
Rationale:
This setting defines the local port range that is used by TCP and UDP to choose the local port. The first number is the first, the second the last local port number.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_local_port_range
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.ip_local_port_range.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_local_port_range

- name: Comment out any occurrences of net.ipv4.ip_local_port_range from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.ip_local_port_range
    replace: '#net.ipv4.ip_local_port_range'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_local_port_range

- name: Ensure sysctl net.ipv4.ip_local_port_range is set to 32768 65535
  sysctl:
    name: net.ipv4.ip_local_port_range
    value: 32768 65535
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_local_port_range

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

# Comment out any occurrences of net.ipv4.ip_local_port_range from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.ip_local_port_range.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.ip_local_port_range" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.ip_local_port_range
#
/sbin/sysctl -q -n -w net.ipv4.ip_local_port_range="32768 65535"

#
# If net.ipv4.ip_local_port_range present in /etc/sysctl.conf, change value to "32768 65535"
#	else, add "net.ipv4.ip_local_port_range = 32768 65535" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.ip_local_port_range")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "32768 65535"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.ip_local_port_range\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.ip_local_port_range\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Enable Kernel Parameter to Use TCP RFC 1337 on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.tcp_rfc1337 kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.tcp_rfc1337=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.tcp_rfc1337 = 1
Rationale:
Enable TCP behavior conformant with RFC 1337. When disabled, if a RST is received in TIME_WAIT state, we close the socket immediately without waiting for the end of the TIME_WAIT period.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_rfc1337
Identifiers and References

References:  BP28(R22)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.tcp_rfc1337.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_rfc1337

- name: Comment out any occurrences of net.ipv4.tcp_rfc1337 from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.tcp_rfc1337
    replace: '#net.ipv4.tcp_rfc1337'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_rfc1337
- name: XCCDF Value sysctl_net_ipv4_tcp_rfc1337_value # promote to variable
  set_fact:
    sysctl_net_ipv4_tcp_rfc1337_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.tcp_rfc1337 is set
  sysctl:
    name: net.ipv4.tcp_rfc1337
    value: '{{ sysctl_net_ipv4_tcp_rfc1337_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_rfc1337

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

# Comment out any occurrences of net.ipv4.tcp_rfc1337 from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.tcp_rfc1337.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.tcp_rfc1337" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_tcp_rfc1337_value='1'


#
# Set runtime for net.ipv4.tcp_rfc1337
#
/sbin/sysctl -q -n -w net.ipv4.tcp_rfc1337="$sysctl_net_ipv4_tcp_rfc1337_value"

#
# If net.ipv4.tcp_rfc1337 present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.tcp_rfc1337 = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.tcp_rfc1337")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_tcp_rfc1337_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.tcp_rfc1337\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.tcp_rfc1337\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces   [ref]

To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.tcp_syncookies = 1
Rationale:
A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001095, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.1, SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.tcp_syncookies.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies

- name: Comment out any occurrences of net.ipv4.tcp_syncookies from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.tcp_syncookies
    replace: '#net.ipv4.tcp_syncookies'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies
- name: XCCDF Value sysctl_net_ipv4_tcp_syncookies_value # promote to variable
  set_fact:
    sysctl_net_ipv4_tcp_syncookies_value: !!str 1
  tags:
    - always

- name: Ensure sysctl net.ipv4.tcp_syncookies is set
  sysctl:
    name: net.ipv4.tcp_syncookies
    value: '{{ sysctl_net_ipv4_tcp_syncookies_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5(1)
  - NIST-800-53-SC-5(2)
  - NIST-800-53-SC-5(3)(a)
  - PCI-DSS-Req-1.4.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_tcp_syncookies

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

# Comment out any occurrences of net.ipv4.tcp_syncookies from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.tcp_syncookies.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.tcp_syncookies" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_net_ipv4_tcp_syncookies_value='1'


#
# Set runtime for net.ipv4.tcp_syncookies
#
/sbin/sysctl -q -n -w net.ipv4.tcp_syncookies="$sysctl_net_ipv4_tcp_syncookies_value"

#
# If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to appropriate value
#	else, add "net.ipv4.tcp_syncookies = value" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.tcp_syncookies")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_tcp_syncookies_value"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.tcp_syncookies\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.tcp_syncookies\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Network Parameters for Hosts Only   Group contains 3 rules
[ref]   If the system is not going to be used as a router, then setting certain kernel parameters ensure that the host will not perform routing of network traffic.

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.all.send_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, 1.4.2, SRG-OS-000480-GPOS-00227, OL07-00-040660, SV-221881r880660_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.all.send_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040660
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

- name: Comment out any occurrences of net.ipv4.conf.all.send_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.all.send_redirects
    replace: '#net.ipv4.conf.all.send_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040660
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

- name: Ensure sysctl net.ipv4.conf.all.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.all.send_redirects
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040660
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_all_send_redirects

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

# Comment out any occurrences of net.ipv4.conf.all.send_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.send_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.all.send_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.conf.all.send_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.all.send_redirects="0"

#
# If net.ipv4.conf.all.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.send_redirects = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.send_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.send_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default   [ref]

To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.conf.default.send_redirects = 0
Rationale:
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-040650, SV-221880r880657_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.conf.default.send_redirects.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040650
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

- name: Comment out any occurrences of net.ipv4.conf.default.send_redirects from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.conf.default.send_redirects
    replace: '#net.ipv4.conf.default.send_redirects'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040650
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

- name: Ensure sysctl net.ipv4.conf.default.send_redirects is set to 0
  sysctl:
    name: net.ipv4.conf.default.send_redirects
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.10.1.1
  - DISA-STIG-OL07-00-040650
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_conf_default_send_redirects

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

# Comment out any occurrences of net.ipv4.conf.default.send_redirects from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.send_redirects.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.conf.default.send_redirects" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.conf.default.send_redirects
#
/sbin/sysctl -q -n -w net.ipv4.conf.default.send_redirects="0"

#
# If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.send_redirects")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.send_redirects\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

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

Rule   Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces   [ref]

To set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command: 
$ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
net.ipv4.ip_forward = 0
Warning:  Certain technologies such as virtual machines, containers, etc. rely on IPv4 forwarding to enable and use networking. Disabling IPv4 forwarding would cause those technologies to stop working. Therefore, this rule should not be used in profiles or benchmarks that target usage of IPv4 forwarding.
Rationale:
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_forward
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.3.1, Req-1.3.2, 1.4.2, SRG-OS-000480-GPOS-00227, OL07-00-040740, SV-221889r880663_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*net.ipv4.ip_forward.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040740
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.3.1
  - PCI-DSS-Req-1.3.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_forward

- name: Comment out any occurrences of net.ipv4.ip_forward from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*net.ipv4.ip_forward
    replace: '#net.ipv4.ip_forward'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040740
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.3.1
  - PCI-DSS-Req-1.3.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_forward

- name: Ensure sysctl net.ipv4.ip_forward is set to 0
  sysctl:
    name: net.ipv4.ip_forward
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040740
  - NIST-800-171-3.1.20
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-SC-5
  - NIST-800-53-SC-7(a)
  - PCI-DSS-Req-1.3.1
  - PCI-DSS-Req-1.3.2
  - PCI-DSSv4-1.4.2
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_net_ipv4_ip_forward

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

# Comment out any occurrences of net.ipv4.ip_forward from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

  matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.ip_forward.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "net.ipv4.ip_forward" matches to preserve user data
      sed -i "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for net.ipv4.ip_forward
#
/sbin/sysctl -q -n -w net.ipv4.ip_forward="0"

#
# If net.ipv4.ip_forward present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.ip_forward = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.ip_forward")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.ip_forward\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.ip_forward\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   File Permissions and Masks   Group contains 7 groups and 44 rules
[ref]   Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access.

Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn.

The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Oracle Linux 7 installations: 
$ mount -t xfs | awk '{print $3}'
For any systems that use a different local filesystem type, modify this command as appropriate.
Group   Verify Permissions on Important Files and Directories   Group contains 1 group and 15 rules
[ref]   Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.
Group   Verify Permissions on Files with Local Account Information and Credentials   Group contains 6 rules

Rule   Verify User Who Owns gshadow File   [ref]

To properly set the owner of /etc/gshadow, run the command: 
$ sudo chown root /etc/gshadow
Rationale:
The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_gshadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/gshadow
  file:
    path: /etc/gshadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/gshadow

Rule   Verify User Who Owns shadow File   [ref]

To properly set the owner of /etc/shadow, run the command: 
$ sudo chown root /etc/shadow
Rationale:
The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_owner_etc_shadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/shadow
  file:
    path: /etc/shadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure
chown 0 /etc/shadow

Rule   Verify Permissions on group File   [ref]

To properly set the permissions of /etc/passwd, run the command: 
$ sudo chmod 0644 /etc/passwd
Rationale:
The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_group
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
  file:
    path: /etc/group
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xs,g-xws,o-xwt /etc/group

Rule   Verify Permissions on gshadow File   [ref]

To properly set the permissions of /etc/gshadow, run the command: 
$ sudo chmod 0000 /etc/gshadow
Rationale:
The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow
  file:
    path: /etc/gshadow
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow

Rule   Verify Permissions on passwd File   [ref]

To properly set the permissions of /etc/passwd, run the command: 
$ sudo chmod 0644 /etc/passwd
Rationale:
If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_passwd
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
  file:
    path: /etc/passwd
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xs,g-xws,o-xwt /etc/passwd

Rule   Verify Permissions on shadow File   [ref]

To properly set the permissions of /etc/shadow, run the command: 
$ sudo chmod 0000 /etc/shadow
Rationale:
The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_etc_shadow
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, 7.2.6, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:low
Strategy:configure
- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/shadow
  file:
    path: /etc/shadow
    mode: u-xwrs,g-xwrs,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-7.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Complexity:low
Disruption:low
Strategy:configure





chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow

Rule   Ensure All World-Writable Directories Are Owned by root user   [ref]

All directories in local partitions which are world-writable should be owned by root. If any world-writable directories are not owned by root, this should be investigated. Following this, the files should be deleted or assigned to root user.
Rationale:
Allowing a user account to own a world-writable directory is undesirable because it allows the owner of that directory to remove or replace any files that may be placed in the directory by other users.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_dir_perms_world_writable_root_owned
Identifiers and References

References:  BP28(R40), CCI-000366, SRG-OS-000480-GPOS-00227, SRG-OS-000138-GPOS-00069


Complexity:low
Disruption:medium
Strategy:restrict
- name: Configure excluded (non local) file systems
  set_fact:
    excluded_fstypes:
    - afs
    - ceph
    - cifs
    - smb3
    - smbfs
    - sshfs
    - ncpfs
    - ncp
    - nfs
    - nfs4
    - gfs
    - gfs2
    - glusterfs
    - gpfs
    - pvfs2
    - ocfs2
    - lustre
    - davfs
    - fuse.sshfs
  tags:
  - dir_perms_world_writable_root_owned
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create empty list of excluded paths
  set_fact:
    excluded_paths: []
  tags:
  - dir_perms_world_writable_root_owned
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Detect nonlocal file systems and add them to excluded paths
  set_fact:
    excluded_paths: '{{ excluded_paths | union([item.mount]) }}'
  loop: '{{ ansible_mounts }}'
  when: item.fstype in excluded_fstypes
  tags:
  - dir_perms_world_writable_root_owned
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Find all directories excluding non-local partitions
  find:
    paths: /
    excludes: excluded_paths
    file_type: directory
    hidden: true
    recurse: true
  register: found_dirs
  tags:
  - dir_perms_world_writable_root_owned
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Create list of world writable directories
  set_fact:
    world_writable_dirs: '{{ found_dirs.files | selectattr(''woth'') | list }}'
  tags:
  - dir_perms_world_writable_root_owned
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Change owner to root on directories which are world writable
  file:
    path: '{{ item.path }}'
    owner: root
  loop: '{{ world_writable_dirs }}'
  ignore_errors: true
  tags:
  - dir_perms_world_writable_root_owned
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy



find / -not -fstype afs -not -fstype ceph -not -fstype cifs -not -fstype smb3 -not -fstype smbfs -not -fstype sshfs -not -fstype ncpfs -not -fstype ncp -not -fstype nfs -not -fstype nfs4 -not -fstype gfs -not -fstype gfs2 -not -fstype glusterfs -not -fstype gpfs -not -fstype pvfs2 -not -fstype ocfs2 -not -fstype lustre -not -fstype davfs -not -fstype fuse.sshfs -type d -perm -0002 -uid +0 -exec chown root {} \;

Rule   Verify that All World-Writable Directories Have Sticky Bits Set   [ref]

When the so-called 'sticky bit' is set on a directory, only the owner of a given file may remove that file from the directory. Without the sticky bit, any user with write access to a directory may remove any file in the directory. Setting the sticky bit prevents users from removing each other's files. In cases where there is no reason for a directory to be world-writable, a better solution is to remove that permission rather than to set the sticky bit. However, if a directory is used by a particular application, consult that application's documentation instead of blindly changing modes.
To set the sticky bit on a world-writable directory DIR, run the following command: 
$ sudo chmod +t DIR
Rationale:
Failing to set the sticky bit on public directories allows unauthorized users to delete files in the directory structure.

The only authorized public directories are those temporary directories supplied with the system, or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system, by users for temporary file storage (such as /tmp), and for directories requiring global read/write access.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_dir_perms_world_writable_sticky_bits
Identifiers and References

References:  BP28(R40), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-001090, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000138-GPOS-00069


Complexity:low
Disruption:low
Strategy:restrict
- name: Get all world-writable directories with no sticky bits set
  shell: |
    set -o pipefail
    df --local -P | awk '{if (NR!=1) print $6}' | xargs -I '{}' find '{}' -xdev -type d \( -perm -0002 -a ! -perm -1000 \) 2>/dev/null
  register: dir_output
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - dir_perms_world_writable_sticky_bits
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure sticky bit is set
  file:
    path: '{{ item }}'
    mode: a+t
  with_items:
  - '{{ dir_output.stdout_lines }}'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - dir_perms_world_writable_sticky_bits
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


df --local -P | awk '{if (NR!=1) print $6}' \
| xargs -I '$6' find '$6' -xdev -type d \
\( -perm -0002 -a ! -perm -1000 \) 2>/dev/null \
-exec chmod a+t {} +

Rule   Ensure All SGID Executables Are Authorized   [ref]

The SGID (set group id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SGID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SGID files. This configuration check considers authorized SGID files which were installed via RPM. It is assumed that when an individual has sudo access to install an RPM and all packages are signed with an organizationally-recognized GPG key, the software should be considered an approved package on the system. Any SGID file not deployed through an RPM will be flagged for further review.
Rationale:
Executable files with the SGID permission run with the privileges of the owner of the file. SGID files of uncertain provenance could allow for unprivileged users to elevate privileges. The presence of these files should be strictly controlled on the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_unauthorized_sgid
Identifiers and References

References:  BP28(R37), BP28(R38), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5

Rule   Ensure All SUID Executables Are Authorized   [ref]

The SUID (set user id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SUID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SUID files. This configuration check considers authorized SUID files which were installed via RPM. It is assumed that when an individual has sudo access to install an RPM and all packages are signed with an organizationally-recognized GPG key, the software should be considered an approved package on the system. Any SUID file not deployed through an RPM will be flagged for further review.
Rationale:
Executable files with the SUID permission run with the privileges of the owner of the file. SUID files of uncertain provenance could allow for unprivileged users to elevate privileges. The presence of these files should be strictly controlled on the system.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_unauthorized_suid
Identifiers and References

References:  BP28(R37), BP28(R38), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5

Rule   Ensure No World-Writable Files Exist   [ref]

It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account. Finally, this applies to real files and not virtual files that are a part of pseudo file systems such as sysfs or procfs.
Rationale:
Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_unauthorized_world_writable
Identifiers and References

References:  BP28(R40), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 2.2.6



find / -xdev -type f -perm -002 -exec chmod o-w {} \;

Rule   Ensure All Files Are Owned by a Group   [ref]

If any files are not owned by a group, then the cause of their lack of group-ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate group. The following command will discover and print any files on local partitions which do not belong to a valid group: 
$ df --local -P | awk '{if (NR!=1) print $6}' | sudo xargs -I '{}' find '{}' -xdev -nogroup
To search all filesystems on a system including network mounted filesystems the following command can be run manually for each partition: 
$ sudo find PARTITION -xdev -nogroup
Warning:  This rule only considers local groups. If you have your groups defined outside /etc/group, the rule won't consider those.
Rationale:
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_ungroupowned
Identifiers and References

References:  BP28(R55), 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10, CCI-000366, CCI-002165, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3, 2.2.6, SRG-OS-000480-GPOS-00227, OL07-00-020330, SV-221725r603260_rule

Rule   Ensure All Files Are Owned by a User   [ref]

If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user. The following command will discover and print any files on local partitions which do not belong to a valid user: 
$ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nouser
To search all filesystems on a system including network mounted filesystems the following command can be run manually for each partition: 
$ sudo find PARTITION -xdev -nouser
Warning:  For this rule to evaluate centralized user accounts, getent must be working properly so that running the command 
getent passwd
returns a list of all users in your organization. If using the System Security Services Daemon (SSSD), 
enumerate = true
must be configured in your organization's domain to return a complete list of users
Warning:  Enabling this rule will result in slower scan times depending on the size of your organization and number of centralized users.
Rationale:
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_no_files_unowned_by_user
Identifiers and References

References:  BP28(R55), 11, 12, 13, 14, 15, 16, 18, 3, 5, 9, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, CCI-000366, CCI-002165, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, 2.2.6, SRG-OS-000480-GPOS-00227, OL07-00-020320, SV-221724r603260_rule

Group   Restrict Partition Mount Options   Group contains 15 rules
[ref]   System partitions can be mounted with certain options that limit what files on those partitions can do. These options are set in the /etc/fstab configuration file, and can be used to make certain types of malicious behavior more difficult.

Rule   Add noexec Option to /boot   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /boot. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /boot.
Rationale:
The /boot partition contains the kernel and the bootloader. No binaries should be executed from this partition after the booting process finishes.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_boot_noexec
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /boot --mountoptions="noexec"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add noexec Option to /boot: Check information associated to mountpoint'
  command: findmnt --fstab '/boot'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /boot: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /boot: If /boot not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /boot
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /boot: Make sure noexec option is part of the to /boot
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "noexec" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /boot: Ensure /boot is mounted with noexec option'
  mount:
    path: /boot
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_noexec
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/boot")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/boot' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /boot in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /boot)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /boot  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "noexec"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
    fi


    if mkdir -p "/boot"; then
        if mountpoint -q "/boot"; then
            mount -o remount --target "/boot"
        fi
    fi
}

perform_remediation

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

Rule   Add nosuid Option to /boot   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /boot. The SUID and SGID permissions should not be required on the boot partition. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /boot.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from boot partitions.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_boot_nosuid
Identifiers and References

References:  BP28(R12), CCI-000366, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:high
Strategy:enable

part /boot --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /boot: Check information associated to mountpoint'
  command: findmnt --fstab '/boot'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /boot: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /boot: If /boot not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /boot
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /boot: Make sure nosuid option is part of the to /boot
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /boot: Ensure /boot is mounted with nosuid option'
  mount:
    path: /boot
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_boot_nosuid
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/boot")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/boot' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /boot in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /boot)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /boot  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/boot"; then
        if mountpoint -q "/boot"; then
            mount -o remount --target "/boot"
        fi
    fi
}

perform_remediation

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

Rule   Add noexec Option to /home   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /home. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /home.
Warning:  OVAL looks for partitions whose mount point is a substring of any interactive user's home directory and validates that noexec option is there. Because of this, there could be false negatives when several partitions share a base substring. For example, if there is a home directory in /var/tmp/user1 and there are partitions mounted in /var and /var/tmp. The noexec option is only expected in /var/tmp, but OVAL will check both.
Bash remediation uses the df command to find out the partition where the home directory is mounted. However, if the directory doesn't exist the remediation won't be applied.
Rationale:
The /home directory contains data of individual users. Binaries in this directory should not be considered as trusted and users should not be able to execute them.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_home_noexec
Identifiers and References

References:  BP28(R12), CCI-000366, CM-6(b), SRG-OS-000480-GPOS-00227


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

function perform_remediation (){

    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" $1)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " $1  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "noexec"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
    fi

    if mkdir -p "$1"; then
        if mountpoint -q "$1"; then
            mount -o remount --target "$1"
        fi
    fi
}

readarray -t home_directories  < \
    <(awk -F':' '{if ($3>=1000 && $3!= 65534) print $6}' /etc/passwd )


for home_directory in "${home_directories[@]}"
do
    if [ -d $home_directory ]; then
        fstab_mount_point=$(df $home_directory | awk '/^\/dev/ {print $6}')
        if  ! grep -qP "^/$|^/lib$|^/opt$|^/usr$|^/bin$|^/sbin$|^/boot$|^/dev$|^/proc$" <<< $fstab_mount_point
        then
            perform_remediation "$fstab_mount_point"
        fi
    fi
done

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

Rule   Add nosuid Option to /home   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /home. The SUID and SGID permissions should not be required in these user data directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /home.
Warning:  OVAL looks for partitions whose mount point is a substring of any interactive user's home directory and validates that noexec option is there. Because of this, there could be false negatives when several partitions share a base substring. For example, if there is a home directory in /var/tmp/user1 and there are partitions mounted in /var and /var/tmp. The noexec option is only expected in /var/tmp, but OVAL will check both.
Bash remediation uses the df command to find out the partition where the home directory is mounted. However, if the directory doesn't exist the remediation won't be applied.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from user home directory partitions.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_home_nosuid
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227, OL07-00-021000, SV-221741r603801_rule


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

function perform_remediation (){

    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" $1)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " $1  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi

    if mkdir -p "$1"; then
        if mountpoint -q "$1"; then
            mount -o remount --target "$1"
        fi
    fi
}

readarray -t home_directories  < \
    <(awk -F':' '{if ($3>=1000 && $3!= 65534) print $6}' /etc/passwd )


for home_directory in "${home_directories[@]}"
do
    if [ -d $home_directory ]; then
        fstab_mount_point=$(df $home_directory | awk '/^\/dev/ {print $6}')
        if  ! grep -qP "^/$|^/lib$|^/opt$|^/usr$|^/bin$|^/sbin$|^/boot$|^/dev$|^/proc$" <<< $fstab_mount_point
        then
            perform_remediation "$fstab_mount_point"
        fi
    fi
done

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

Rule   Add nodev Option to Non-Root Local Partitions   [ref]

The nodev mount option prevents files from being interpreted as character or block devices. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of any non-root local partitions.
Rationale:
The nodev mount option prevents files from being interpreted as character or block devices. The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails, for which it is not advised to set nodev on these filesystems.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_nodev_nonroot_local_partitions
Identifiers and References

References:  BP28(R12), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:high
Strategy:configure
- name: Ensure non-root local partitions are mounted with nodev option
  mount:
    path: '{{ item.mount }}'
    src: '{{ item.device }}'
    opts: '{{ item.options }},nodev'
    state: mounted
    fstype: '{{ item.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - item.mount is match('/\w')
  - item.options is not search('nodev')
  with_items:
  - '{{ ansible_facts.mounts }}'
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_nodev_nonroot_local_partitions
  - no_reboot_needed


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

MOUNT_OPTION="nodev"
# Create array of local non-root partitions
readarray -t partitions_records < <(findmnt --mtab --raw --evaluate | grep "^/\w" | grep "\s/dev/\w")

# Create array of polyinstantiated directories, in case one of them is found in mtab
readarray -t polyinstantiated_dirs < \
    <(grep -oP "^\s*[^#\s]+\s+\S+" /etc/security/namespace.conf | grep -oP "(?<=\s)\S+?(?=/?\$)")


for partition_record in "${partitions_records[@]}"; do
    # Get all important information for fstab
    mount_point="$(echo ${partition_record} | cut -d " " -f1)"
    device="$(echo ${partition_record} | cut -d " " -f2)"
    device_type="$(echo ${partition_record} | cut -d " " -f3)"
    if ! printf '%s\0' "${polyinstantiated_dirs[@]}" | grep -qxzF "$mount_point"; then
        # device and device_type will be used only in case when the device doesn't have fstab record
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" $mount_point)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|$MOUNT_OPTION)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            echo "$device $mount_point $device_type defaults,${previous_mount_opts}$MOUNT_OPTION 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "$MOUNT_OPTION"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,$MOUNT_OPTION|" /etc/fstab
        fi
        if mkdir -p "$mount_point"; then
            if mountpoint -q "$mount_point"; then
                mount -o remount --target "$mount_point"
            fi
        fi
    fi
done

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

Rule   Add nosuid Option to /opt   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /opt. The SUID and SGID permissions should not be required in this directory. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /opt.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. The /opt directory contains additional software packages. Users should not be able to execute SUID or SGID binaries from this directory.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_opt_nosuid
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /opt --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /opt: Check information associated to mountpoint'
  command: findmnt --fstab '/opt'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_opt_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /opt: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_opt_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /opt: If /opt not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /opt
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_opt_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /opt: Make sure nosuid option is part of the to /opt
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_opt_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /opt: Ensure /opt is mounted with nosuid option'
  mount:
    path: /opt
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_opt_nosuid
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/opt")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/opt' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /opt in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /opt)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /opt  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/opt"; then
        if mountpoint -q "/opt"; then
            mount -o remount --target "/opt"
        fi
    fi
}

perform_remediation

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

Rule   Add nosuid Option to /srv   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /srv. The SUID and SGID permissions should not be required in this directory. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /srv.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. The /srv directory contains files served by various network services such as FTP. Users should not be able to execute SUID or SGID binaries from this directory.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_srv_nosuid
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /srv --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /srv: Check information associated to mountpoint'
  command: findmnt --fstab '/srv'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_srv_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /srv: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_srv_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /srv: If /srv not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /srv
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_srv_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /srv: Make sure nosuid option is part of the to /srv
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_srv_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /srv: Ensure /srv is mounted with nosuid option'
  mount:
    path: /srv
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_srv_nosuid
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/srv")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/srv' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /srv in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /srv)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /srv  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/srv"; then
        if mountpoint -q "/srv"; then
            mount -o remount --target "/srv"
        fi
    fi
}

perform_remediation

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

Rule   Add noexec Option to /tmp   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.
Rationale:
Allowing users to execute binaries from world-writable directories such as /tmp should never be necessary in normal operation and can expose the system to potential compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_tmp_noexec
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /tmp --mountoptions="noexec"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add noexec Option to /tmp: Check information associated to mountpoint'
  command: findmnt --fstab '/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /tmp: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /tmp: If /tmp not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /tmp
    - ''
    - ''
    - defaults
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /tmp: Make sure noexec option is part of the to /tmp
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - mount_info is defined and "noexec" not in mount_info.options
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /tmp: Ensure /tmp is mounted with noexec option'
  mount:
    path: /tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_noexec
  - no_reboot_needed


# Remediation is applicable only in certain platforms
if ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null ); then

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/tmp")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /tmp)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /tmp  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "noexec"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
    fi


    if mkdir -p "/tmp"; then
        if mountpoint -q "/tmp"; then
            mount -o remount --target "/tmp"
        fi
    fi
}

perform_remediation

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

Rule   Add nosuid Option to /tmp   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /tmp. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_tmp_nosuid
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /tmp --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /tmp: Check information associated to mountpoint'
  command: findmnt --fstab '/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /tmp: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /tmp: If /tmp not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /tmp
    - ''
    - ''
    - defaults
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /tmp: Make sure nosuid option is part of the to /tmp
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /tmp: Ensure /tmp is mounted with nosuid option'
  mount:
    path: /tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/tmp" in ansible_mounts | map(attribute="mount") | list )
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_tmp_nosuid
  - no_reboot_needed


# Remediation is applicable only in certain platforms
if ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null ); then

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/tmp")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /tmp)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /tmp  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/tmp"; then
        if mountpoint -q "/tmp"; then
            mount -o remount --target "/tmp"
        fi
    fi
}

perform_remediation

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

Rule   Add noexec Option to /var/log   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /var/log. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.
Rationale:
Allowing users to execute binaries from directories containing log files such as /var/log should never be necessary in normal operation and can expose the system to potential compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_noexec
Identifiers and References

References:  BP28(R12), CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /var/log --mountoptions="noexec"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add noexec Option to /var/log: Check information associated to mountpoint'
  command: findmnt --fstab '/var/log'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/log: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/log: If /var/log not mounted, craft mount_info
    manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /var/log
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/log: Make sure noexec option is part of the to
    /var/log options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "noexec" not in mount_info.options
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/log: Ensure /var/log is mounted with noexec option'
  mount:
    path: /var/log
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_noexec
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/var/log")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /var/log)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /var/log  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "noexec"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
    fi


    if mkdir -p "/var/log"; then
        if mountpoint -q "/var/log"; then
            mount -o remount --target "/var/log"
        fi
    fi
}

perform_remediation

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

Rule   Add nosuid Option to /var/log   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /var/log. The SUID and SGID permissions should not be required in directories containing log files. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for log files.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_log_nosuid
Identifiers and References

References:  BP28(R12), CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /var/log --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /var/log: Check information associated to mountpoint'
  command: findmnt --fstab '/var/log'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/log: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/log: If /var/log not mounted, craft mount_info
    manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /var/log
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/log: Make sure nosuid option is part of the to
    /var/log options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/log: Ensure /var/log is mounted with nosuid option'
  mount:
    path: /var/log
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - NIST-800-53-AC-6
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-MP-7
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_log_nosuid
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/var/log")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /var/log)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /var/log  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/var/log"; then
        if mountpoint -q "/var/log"; then
            mount -o remount --target "/var/log"
        fi
    fi
}

perform_remediation

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

Rule   Add noexec Option to /var   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /var. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var.
Rationale:
The /var directory contains variable system data such as logs, mails and caches. No binaries should be executed from this directory.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_noexec
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /var --mountoptions="noexec"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add noexec Option to /var: Check information associated to mountpoint'
  command: findmnt --fstab '/var'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var: If /var not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /var
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var: Make sure noexec option is part of the to /var
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "noexec" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var: Ensure /var is mounted with noexec option'
  mount:
    path: /var
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_noexec
  - no_reboot_needed


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/var")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/var' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /var)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /var  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "noexec"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
    fi


    if mkdir -p "/var"; then
        if mountpoint -q "/var"; then
            mount -o remount --target "/var"
        fi
    fi
}

perform_remediation

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

Rule   Add nosuid Option to /var   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /var. The SUID and SGID permissions should not be required for this directory. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var.
Rationale:
The presence of SUID and SGID executables should be tightly controlled.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_nosuid
Identifiers and References

References:  BP28(R12)


Complexity:low
Disruption:high
Strategy:enable

part /var --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /var: Check information associated to mountpoint'
  command: findmnt --fstab '/var'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_var_nosuid
  - no_reboot_needed
  - unknown_severity

- name: 'Add nosuid Option to /var: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_var_nosuid
  - no_reboot_needed
  - unknown_severity

- name: 'Add nosuid Option to /var: If /var not mounted, craft mount_info manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /var
    - ''
    - ''
    - defaults
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_var_nosuid
  - no_reboot_needed
  - unknown_severity

- name: 'Add nosuid Option to /var: Make sure nosuid option is part of the to /var
    options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_var_nosuid
  - no_reboot_needed
  - unknown_severity

- name: 'Add nosuid Option to /var: Ensure /var is mounted with nosuid option'
  mount:
    path: /var
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - mount_option_var_nosuid
  - no_reboot_needed
  - unknown_severity


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

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/var")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/var' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /var)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /var  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/var"; then
        if mountpoint -q "/var"; then
            mount -o remount --target "/var"
        fi
    fi
}

perform_remediation

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

Rule   Add noexec Option to /var/tmp   [ref]

The noexec mount option can be used to prevent binaries from being executed out of /var/tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.
Rationale:
Allowing users to execute binaries from world-writable directories such as /var/tmp should never be necessary in normal operation and can expose the system to potential compromise.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_tmp_noexec
Identifiers and References

References:  BP28(R12), CCI-001764, SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /var/tmp --mountoptions="noexec"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add noexec Option to /var/tmp: Check information associated to mountpoint'
  command: findmnt --fstab '/var/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "/var/tmp" in ansible_mounts | map(attribute="mount") | list
    )
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/tmp: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/tmp: If /var/tmp not mounted, craft mount_info
    manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /var/tmp
    - ''
    - ''
    - defaults
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/tmp: Make sure noexec option is part of the to
    /var/tmp options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
      }) }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - mount_info is defined and "noexec" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_noexec
  - no_reboot_needed

- name: 'Add noexec Option to /var/tmp: Ensure /var/tmp is mounted with noexec option'
  mount:
    path: /var/tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_noexec
  - no_reboot_needed


# Remediation is applicable only in certain platforms
if ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null ); then

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/var/tmp")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /var/tmp)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /var/tmp  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "noexec"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
    fi


    if mkdir -p "/var/tmp"; then
        if mountpoint -q "/var/tmp"; then
            mount -o remount --target "/var/tmp"
        fi
    fi
}

perform_remediation

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

Rule   Add nosuid Option to /var/tmp   [ref]

The nosuid mount option can be used to prevent execution of setuid programs in /var/tmp. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.
Rationale:
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nosuid
Identifiers and References

References:  BP28(R12), CCI-001764, SRG-OS-000368-GPOS-00154


Complexity:low
Disruption:high
Strategy:enable

part /var/tmp --mountoptions="nosuid"

Complexity:low
Disruption:high
Strategy:configure
- name: 'Add nosuid Option to /var/tmp: Check information associated to mountpoint'
  command: findmnt --fstab '/var/tmp'
  register: device_name
  failed_when: device_name.rc > 1
  changed_when: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "/var/tmp" in ansible_mounts | map(attribute="mount") | list
    )
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/tmp: Create mount_info dictionary variable'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - '{{ device_name.stdout_lines[0].split() | list | lower }}'
  - '{{ device_name.stdout_lines[1].split() | list }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - device_name.stdout is defined and device_name.stdout_lines is defined
  - (device_name.stdout | length > 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/tmp: If /var/tmp not mounted, craft mount_info
    manually'
  set_fact:
    mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
  with_together:
  - - target
    - source
    - fstype
    - options
  - - /var/tmp
    - ''
    - ''
    - defaults
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - ("--fstab" | length == 0)
  - (device_name.stdout | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/tmp: Make sure nosuid option is part of the to
    /var/tmp options'
  set_fact:
    mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
      }) }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - mount_info is defined and "nosuid" not in mount_info.options
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_nosuid
  - no_reboot_needed

- name: 'Add nosuid Option to /var/tmp: Ensure /var/tmp is mounted with nosuid option'
  mount:
    path: /var/tmp
    src: '{{ mount_info.source }}'
    opts: '{{ mount_info.options }}'
    state: mounted
    fstype: '{{ mount_info.fstype }}'
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "/var/tmp" in ansible_mounts | map(attribute="mount") | list )
  - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
    | length == 0)
  tags:
  - configure_strategy
  - high_disruption
  - low_complexity
  - medium_severity
  - mount_option_var_tmp_nosuid
  - no_reboot_needed


# Remediation is applicable only in certain platforms
if ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null ); then

function perform_remediation {
    
        mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" "/var/tmp")"

    grep "$mount_point_match_regexp" -q /etc/fstab \
        || { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
    


    mount_point_match_regexp="$(printf "[[:space:]]%s[[:space:]]" /var/tmp)"

    # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
    if ! grep "$mount_point_match_regexp" /etc/fstab; then
        # runtime opts without some automatic kernel/userspace-added defaults
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                    | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
        [ "$previous_mount_opts" ] && previous_mount_opts+=","
        echo " /var/tmp  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
    # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
    elif ! grep "$mount_point_match_regexp" /etc/fstab | grep "nosuid"; then
        previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
        sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
    fi


    if mkdir -p "/var/tmp"; then
        if mountpoint -q "/var/tmp"; then
            mount -o remount --target "/var/tmp"
        fi
    fi
}

perform_remediation

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Restrict Programs from Dangerous Execution Patterns   Group contains 3 groups and 14 rules
[ref]   The recommendations in this section are designed to ensure that the system's features to protect against potentially dangerous program execution are activated. These protections are applied at the system initialization or kernel level, and defend against certain types of badly-configured or compromised programs.
Group   Disable Core Dumps   Group contains 1 rule
[ref]   A core dump file is the memory image of an executable program when it was terminated by the operating system due to errant behavior. In most cases, only software developers legitimately need to access these files. The core dump files may also contain sensitive information, or unnecessarily occupy large amounts of disk space.

Once a hard limit is set in /etc/security/limits.conf, or to a file within the /etc/security/limits.d/ directory, a user cannot increase that limit within his or her own session. If access to core dumps is required, consider restricting them to only certain users or groups. See the limits.conf man page for more information.

The core dumps of setuid programs are further protected. The sysctl variable fs.suid_dumpable controls whether the kernel allows core dumps from these programs at all. The default value of 0 is recommended.

Rule   Disable Core Dumps for SUID programs   [ref]

To set the runtime status of the fs.suid_dumpable kernel parameter, run the following command: 
$ sudo sysctl -w fs.suid_dumpable=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
fs.suid_dumpable = 0
Rationale:
The core dump of a setuid program is more likely to contain sensitive data, as the program itself runs with greater privileges than the user who initiated execution of the program. Disabling the ability for any setuid program to write a core file decreases the risk of unauthorized access of such data.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_fs_suid_dumpable
Identifiers and References

References:  BP28(R23), 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), SI-11(a), SI-11(b), 3.3.1.1, 3.3.1.2, 3.3.1.3


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*fs.suid_dumpable.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3.1.1
  - PCI-DSSv4-3.3.1.2
  - PCI-DSSv4-3.3.1.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: Comment out any occurrences of fs.suid_dumpable from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*fs.suid_dumpable
    replace: '#fs.suid_dumpable'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3.1.1
  - PCI-DSSv4-3.3.1.2
  - PCI-DSSv4-3.3.1.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: Ensure sysctl fs.suid_dumpable is set to 0
  sysctl:
    name: fs.suid_dumpable
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3.1.1
  - PCI-DSSv4-3.3.1.2
  - PCI-DSSv4-3.3.1.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

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

# Comment out any occurrences of fs.suid_dumpable from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for fs.suid_dumpable
#
/sbin/sysctl -q -n -w fs.suid_dumpable="0"

#
# If fs.suid_dumpable present in /etc/sysctl.conf, change value to "0"
#	else, add "fs.suid_dumpable = 0" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

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

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Enable ExecShield   Group contains 2 rules
[ref]   ExecShield describes kernel features that provide protection against exploitation of memory corruption errors such as buffer overflows. These features include random placement of the stack and other memory regions, prevention of execution in memory that should only hold data, and special handling of text buffers. These protections are enabled by default on 32-bit systems and controlled through sysctl variables kernel.exec-shield and kernel.randomize_va_space. On the latest 64-bit systems, kernel.exec-shield cannot be enabled or disabled with sysctl.

Rule   Restrict Exposed Kernel Pointer Addresses Access   [ref]

To set the runtime status of the kernel.kptr_restrict kernel parameter, run the following command: 
$ sudo sysctl -w kernel.kptr_restrict=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.kptr_restrict = 2
Rationale:
Exposing kernel pointers (through procfs or seq_printf()) exposes kernel writeable structures which may contain functions pointers. If a write vulnerability occurs in the kernel, allowing write access to any of this structure, the kernel can be compromised. This option disallow any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with 0.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_kptr_restrict
Identifiers and References

References:  BP28(R23), CCI-002824, CCI-000366, CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4, SC-30, SC-30(2), SC-30(5), CM-6(a), SRG-OS-000132-GPOS-00067, SRG-OS-000433-GPOS-00192, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.kptr_restrict.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - NIST-800-53-SC-30(5)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_kptr_restrict

- name: Comment out any occurrences of kernel.kptr_restrict from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.kptr_restrict
    replace: '#kernel.kptr_restrict'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - NIST-800-53-SC-30(5)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_kptr_restrict
- name: XCCDF Value sysctl_kernel_kptr_restrict_value # promote to variable
  set_fact:
    sysctl_kernel_kptr_restrict_value: !!str 2
  tags:
    - always

- name: Ensure sysctl kernel.kptr_restrict is set
  sysctl:
    name: kernel.kptr_restrict
    value: '{{ sysctl_kernel_kptr_restrict_value }}'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - NIST-800-53-SC-30(5)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_kptr_restrict

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

# Comment out any occurrences of kernel.kptr_restrict from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"

sysctl_kernel_kptr_restrict_value='2'


#
# Set runtime for kernel.kptr_restrict
#
/sbin/sysctl -q -n -w kernel.kptr_restrict="$sysctl_kernel_kptr_restrict_value"

#
# If kernel.kptr_restrict present in /etc/sysctl.conf, change value to appropriate value
#	else, add "kernel.kptr_restrict = value" to /etc/sysctl.conf
#

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

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

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

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

Rule   Enable Randomized Layout of Virtual Address Space   [ref]

To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command: 
$ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.randomize_va_space = 2
Rationale:
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space
Identifiers and References

References:  BP28(R23), 3.1.7, CCI-000366, CCI-002824, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4, SC-30, SC-30(2), CM-6(a), Req-2.2.1, 2.2.3, SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227, OL07-00-040201, SV-221846r880630_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.randomize_va_space.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040201
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-2.2.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Comment out any occurrences of kernel.randomize_va_space from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.randomize_va_space
    replace: '#kernel.randomize_va_space'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040201
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-2.2.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Ensure sysctl kernel.randomize_va_space is set to 2
  sysctl:
    name: kernel.randomize_va_space
    value: '2'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040201
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-2.2.3
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

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

# Comment out any occurrences of kernel.randomize_va_space from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.randomize_va_space
#
/sbin/sysctl -q -n -w kernel.randomize_va_space="2"

#
# If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
#	else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "2"

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

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Memory Poisoning   Group contains 2 rules
[ref]   Memory Poisoning consists of writing a special value to uninitialized or freed memory. Poisoning can be used as a mechanism to prevent leak of information and detection of corrupted memory.

Rule   Enable page allocator poisoning   [ref]

To enable poisoning of free pages, add the argument page_poison=1 to the default GRUB 2 command line for the Linux operating system. To ensure that page_poison=1 is added as a kernel command line argument to newly installed kernels, add page_poison=1 to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... page_poison=1 ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="page_poison=1"
Rationale:
Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_page_poison_argument
Identifiers and References

References:  BP28(R8), CCI-001084, CM-6(a), SRG-OS-000480-GPOS-00227, SRG-OS-000134-GPOS-00068


[customizations.kernel]
append = "page_poison=1"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_page_poison_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Check page_poison argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*page_poison=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_page_poison_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Replace existing page_poison argument
  replace:
    path: /etc/default/grub
    regexp: page_poison=\w+
    replace: page_poison=1
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  - argcheck.rc == 0
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_page_poison_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add page_poison argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 page_poison=1"
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  - argcheck.rc != 0
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_page_poison_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="page_poison=1"
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_page_poison_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q grub2-common; }; then

# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*page_poison=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an page_poison= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)page_poison=[^[:space:]]\+\(.*\"\)/\1page_poison=1\2/"  '/etc/default/grub'
else
       # no page_poison=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 page_poison=1\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=page_poison=1

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

Rule   Enable SLUB/SLAB allocator poisoning   [ref]

To enable poisoning of SLUB/SLAB objects, add the argument slub_debug=FZP to the default GRUB 2 command line for the Linux operating system. To ensure that slub_debug=FZP is added as a kernel command line argument to newly installed kernels, add slub_debug=FZP to the default Grub2 command line for Linux operating systems. Modify the line within /etc/default/grub as shown below: 
GRUB_CMDLINE_LINUX="... slub_debug=FZP ..."
Run the following command to update command line for already installed kernels:
# grubby --update-kernel=ALL --args="slub_debug=FZP"
Rationale:
Poisoning writes an arbitrary value to freed objects, so any modification or reference to that object after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_grub2_slub_debug_argument
Identifiers and References

References:  BP28(R8), CCI-001084, CM-6(a), SRG-OS-000433-GPOS-00192, SRG-OS-000134-GPOS-00068


[customizations.kernel]
append = "slub_debug=FZP"

Complexity:medium
Disruption:low
Reboot:true
Strategy:restrict
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_slub_debug_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy
- name: XCCDF Value var_slub_debug_options # promote to variable
  set_fact:
    var_slub_debug_options: !!str FZP
  tags:
    - always

- name: Check slub_debug argument exists
  command: grep 'GRUB_CMDLINE_LINUX.*slub_debug=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_slub_debug_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Replace existing slub_debug argument
  replace:
    path: /etc/default/grub
    regexp: slub_debug=\w+
    replace: slub_debug={{ var_slub_debug_options }}
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  - argcheck.rc == 0
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_slub_debug_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Add slub_debug argument
  replace:
    path: /etc/default/grub
    regexp: (GRUB_CMDLINE_LINUX=.*)"
    replace: \1 slub_debug={{ var_slub_debug_options }}"
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  - argcheck.rc != 0
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_slub_debug_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy

- name: Update grub defaults and the bootloader menu
  command: /sbin/grubby --update-kernel=ALL --args="slub_debug={{ var_slub_debug_options
    }}"
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"grub2-common" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - grub2_slub_debug_argument
  - low_disruption
  - medium_complexity
  - medium_severity
  - reboot_required
  - restrict_strategy


# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { rpm --quiet -q grub2-common; }; then

var_slub_debug_options='FZP'




# Correct the form of default kernel command line in GRUB
if grep -q '^GRUB_CMDLINE_LINUX=.*slub_debug=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an slub_debug= arg already exists
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)slub_debug=[^[:space:]]\+\(.*\"\)/\1slub_debug=$var_slub_debug_options\2/"  '/etc/default/grub'
else
       # no slub_debug=arg is present, append it
       sed -i "s/\(^GRUB_CMDLINE_LINUX=\".*\)\"/\1 slub_debug=$var_slub_debug_options\"/"  '/etc/default/grub'
fi
grubby --update-kernel=ALL --args=slub_debug=$var_slub_debug_options

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

Rule   Restrict Access to Kernel Message Buffer   [ref]

To set the runtime status of the kernel.dmesg_restrict kernel parameter, run the following command: 
$ sudo sysctl -w kernel.dmesg_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.dmesg_restrict = 1
Rationale:
Unprivileged access to the kernel syslog can expose sensitive kernel address information.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_dmesg_restrict
Identifiers and References

References:  BP28(R23), 3.1.5, CCI-001090, CCI-001314, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), SI-11(a), SI-11(b), SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069, OL07-00-010375, SV-255901r880627_rule


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.dmesg_restrict.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-010375
  - NIST-800-171-3.1.5
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - disable_strategy
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required
  - sysctl_kernel_dmesg_restrict

- name: Comment out any occurrences of kernel.dmesg_restrict from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.dmesg_restrict
    replace: '#kernel.dmesg_restrict'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-010375
  - NIST-800-171-3.1.5
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - disable_strategy
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required
  - sysctl_kernel_dmesg_restrict

- name: Ensure sysctl kernel.dmesg_restrict is set to 1
  sysctl:
    name: kernel.dmesg_restrict
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-010375
  - NIST-800-171-3.1.5
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - disable_strategy
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required
  - sysctl_kernel_dmesg_restrict

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

# Comment out any occurrences of kernel.dmesg_restrict from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.dmesg_restrict
#
/sbin/sysctl -q -n -w kernel.dmesg_restrict="1"

#
# If kernel.dmesg_restrict present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.dmesg_restrict = 1" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

Rule   Kernel panic on oops   [ref]

To set the runtime status of the kernel.panic_on_oops kernel parameter, run the following command: 
$ sudo sysctl -w kernel.panic_on_oops=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.panic_on_oops = 1
Warning:  The system may start to panic when it normally wouldn't. A non-catastrophic error that would have allowed the system to continue operating will now result in a panic.
Rationale:
An attacker trying to exploit the kernel may trigger kernel OOPSes, panicking the system will impede them from continuing.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_panic_on_oops
Identifiers and References

References:  BP28(R9)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.panic_on_oops.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_panic_on_oops

- name: Comment out any occurrences of kernel.panic_on_oops from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.panic_on_oops
    replace: '#kernel.panic_on_oops'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_panic_on_oops

- name: Ensure sysctl kernel.panic_on_oops is set to 1
  sysctl:
    name: kernel.panic_on_oops
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_panic_on_oops

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

# Comment out any occurrences of kernel.panic_on_oops from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.panic_on_oops
#
/sbin/sysctl -q -n -w kernel.panic_on_oops="1"

#
# If kernel.panic_on_oops present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.panic_on_oops = 1" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

Rule   Limit CPU consumption of the Perf system   [ref]

To set the runtime status of the kernel.perf_cpu_time_max_percent kernel parameter, run the following command: 
$ sudo sysctl -w kernel.perf_cpu_time_max_percent=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.perf_cpu_time_max_percent = 1
Rationale:
The kernel.perf_cpu_time_max_percent configures a treshold of maximum percentile of CPU that can be used by Perf system. Restricting usage of Perf system decreases risk of potential availability problems.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_perf_cpu_time_max_percent
Identifiers and References

References:  BP28(R23)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.perf_cpu_time_max_percent.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_perf_cpu_time_max_percent

- name: Comment out any occurrences of kernel.perf_cpu_time_max_percent from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.perf_cpu_time_max_percent
    replace: '#kernel.perf_cpu_time_max_percent'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_perf_cpu_time_max_percent

- name: Ensure sysctl kernel.perf_cpu_time_max_percent is set to 1
  sysctl:
    name: kernel.perf_cpu_time_max_percent
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_perf_cpu_time_max_percent

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

# Comment out any occurrences of kernel.perf_cpu_time_max_percent from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.perf_cpu_time_max_percent
#
/sbin/sysctl -q -n -w kernel.perf_cpu_time_max_percent="1"

#
# If kernel.perf_cpu_time_max_percent present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.perf_cpu_time_max_percent = 1" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

Rule   Limit sampling frequency of the Perf system   [ref]

To set the runtime status of the kernel.perf_event_max_sample_rate kernel parameter, run the following command: 
$ sudo sysctl -w kernel.perf_event_max_sample_rate=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.perf_event_max_sample_rate = 1
Rationale:
The kernel.perf_event_max_sample_rate parameter configures maximum frequency of collecting of samples for the Perf system. It is expressed in samples per second. Restricting usage of Perf system decreases risk of potential availability problems.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_perf_event_max_sample_rate
Identifiers and References

References:  BP28(R23)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.perf_event_max_sample_rate.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_perf_event_max_sample_rate

- name: Comment out any occurrences of kernel.perf_event_max_sample_rate from config
    files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.perf_event_max_sample_rate
    replace: '#kernel.perf_event_max_sample_rate'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_perf_event_max_sample_rate

- name: Ensure sysctl kernel.perf_event_max_sample_rate is set to 1
  sysctl:
    name: kernel.perf_event_max_sample_rate
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_perf_event_max_sample_rate

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

# Comment out any occurrences of kernel.perf_event_max_sample_rate from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.perf_event_max_sample_rate
#
/sbin/sysctl -q -n -w kernel.perf_event_max_sample_rate="1"

#
# If kernel.perf_event_max_sample_rate present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.perf_event_max_sample_rate = 1" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

Rule   Disallow kernel profiling by unprivileged users   [ref]

To set the runtime status of the kernel.perf_event_paranoid kernel parameter, run the following command: 
$ sudo sysctl -w kernel.perf_event_paranoid=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.perf_event_paranoid = 2
Rationale:
Kernel profiling can reveal sensitive information about kernel behaviour.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_perf_event_paranoid
Identifiers and References

References:  BP28(R23), CCI-001090, AC-6, FMT_SMF_EXT.1, SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.perf_event_paranoid.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - disable_strategy
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required
  - sysctl_kernel_perf_event_paranoid

- name: Comment out any occurrences of kernel.perf_event_paranoid from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.perf_event_paranoid
    replace: '#kernel.perf_event_paranoid'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - disable_strategy
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required
  - sysctl_kernel_perf_event_paranoid

- name: Ensure sysctl kernel.perf_event_paranoid is set to 2
  sysctl:
    name: kernel.perf_event_paranoid
    value: '2'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AC-6
  - disable_strategy
  - low_complexity
  - low_severity
  - medium_disruption
  - reboot_required
  - sysctl_kernel_perf_event_paranoid

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

# Comment out any occurrences of kernel.perf_event_paranoid from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.perf_event_paranoid
#
/sbin/sysctl -q -n -w kernel.perf_event_paranoid="2"

#
# If kernel.perf_event_paranoid present in /etc/sysctl.conf, change value to "2"
#	else, add "kernel.perf_event_paranoid = 2" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "2"

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

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

Rule   Configure maximum number of process identifiers   [ref]

To set the runtime status of the kernel.pid_max kernel parameter, run the following command: 
$ sudo sysctl -w kernel.pid_max=65536
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.pid_max = 65536
Rationale:
The kernel.pid_max parameter configures upper limit on process identifiers (PID). If this number is not high enough, it might happen that forking of new processes is not possible, because all available PIDs are exhausted. Increasing this number enhances availability.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_pid_max
Identifiers and References

References:  BP28(R23)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.pid_max.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_pid_max

- name: Comment out any occurrences of kernel.pid_max from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.pid_max
    replace: '#kernel.pid_max'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_pid_max

- name: Ensure sysctl kernel.pid_max is set to 65536
  sysctl:
    name: kernel.pid_max
    value: '65536'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_pid_max

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

# Comment out any occurrences of kernel.pid_max from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.pid_max
#
/sbin/sysctl -q -n -w kernel.pid_max="65536"

#
# If kernel.pid_max present in /etc/sysctl.conf, change value to "65536"
#	else, add "kernel.pid_max = 65536" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "65536"

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

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

Rule   Disallow magic SysRq key   [ref]

To set the runtime status of the kernel.sysrq kernel parameter, run the following command: 
$ sudo sysctl -w kernel.sysrq=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.sysrq = 0
Rationale:
The Magic SysRq key allows sending certain commands directly to the running kernel. It can dump various system and process information, potentially revealing sensitive information. It can also reboot or shutdown the machine, disturbing its availability.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_sysrq
Identifiers and References

References:  BP28(R23)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.sysrq.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_sysrq

- name: Comment out any occurrences of kernel.sysrq from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.sysrq
    replace: '#kernel.sysrq'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_sysrq

- name: Ensure sysctl kernel.sysrq is set to 0
  sysctl:
    name: kernel.sysrq
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_sysrq

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

# Comment out any occurrences of kernel.sysrq from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.sysrq
#
/sbin/sysctl -q -n -w kernel.sysrq="0"

#
# If kernel.sysrq present in /etc/sysctl.conf, change value to "0"
#	else, add "kernel.sysrq = 0" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

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

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

Rule   Restrict usage of ptrace to descendant processes   [ref]

To set the runtime status of the kernel.yama.ptrace_scope kernel parameter, run the following command: 
$ sudo sysctl -w kernel.yama.ptrace_scope=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
kernel.yama.ptrace_scope = 1
Rationale:
Unrestricted usage of ptrace allows compromised binaries to run ptrace on another processes of the user. Like this, the attacker can steal sensitive information from the target processes (e.g. SSH sessions, web browser, ...) without any additional assistance from the user (i.e. without resorting to phishing).
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_kernel_yama_ptrace_scope
Identifiers and References

References:  BP28(R25), CCI-000366, SC-7(10), SRG-OS-000132-GPOS-00067, SRG-OS-000480-GPOS-00227


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*kernel.yama.ptrace_scope.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SC-7(10)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_yama_ptrace_scope

- name: Comment out any occurrences of kernel.yama.ptrace_scope from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.yama.ptrace_scope
    replace: '#kernel.yama.ptrace_scope'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SC-7(10)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_yama_ptrace_scope

- name: Ensure sysctl kernel.yama.ptrace_scope is set to 1
  sysctl:
    name: kernel.yama.ptrace_scope
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SC-7(10)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_yama_ptrace_scope

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

# Comment out any occurrences of kernel.yama.ptrace_scope from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.yama.ptrace_scope
#
/sbin/sysctl -q -n -w kernel.yama.ptrace_scope="1"

#
# If kernel.yama.ptrace_scope present in /etc/sysctl.conf, change value to "1"
#	else, add "kernel.yama.ptrace_scope = 1" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

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

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

Rule   Prevent applications from mapping low portion of virtual memory   [ref]

To set the runtime status of the vm.mmap_min_addr kernel parameter, run the following command: 
$ sudo sysctl -w vm.mmap_min_addr=65536
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: 
vm.mmap_min_addr = 65536
Rationale:
The vm.mmap_min_addr parameter specifies the minimum virtual address that a process is allowed to mmap. Allowing a process to mmap low portion of virtual memory can have security implications such as such as heightened risk of kernel null pointer dereference defects.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sysctl_vm_mmap_min_addr
Identifiers and References

References:  BP28(R23)


Complexity:low
Disruption:medium
Reboot:true
Strategy:disable
- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    contains: ^[\s]*vm.mmap_min_addr.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_vm_mmap_min_addr

- name: Comment out any occurrences of vm.mmap_min_addr from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*vm.mmap_min_addr
    replace: '#vm.mmap_min_addr'
  loop: '{{ find_sysctl_d.files }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_vm_mmap_min_addr

- name: Ensure sysctl vm.mmap_min_addr is set to 65536
  sysctl:
    name: vm.mmap_min_addr
    value: '65536'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_vm_mmap_min_addr

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

# Comment out any occurrences of vm.mmap_min_addr from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf; do

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

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for vm.mmap_min_addr
#
/sbin/sysctl -q -n -w vm.mmap_min_addr="65536"

#
# If vm.mmap_min_addr present in /etc/sysctl.conf, change value to "65536"
#	else, add "vm.mmap_min_addr = 65536" to /etc/sysctl.conf
#

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

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "65536"

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

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   SELinux   Group contains 1 group and 2 rules
[ref]   SELinux is a feature of the Linux kernel which can be used to guard against misconfigured or compromised programs. SELinux enforces the idea that programs should be limited in what files they can access and what actions they can take.

The default SELinux policy, as configured on Oracle Linux 7, has been sufficiently developed and debugged that it should be usable on almost any system with minimal configuration and a small amount of system administrator training. This policy prevents system services - including most of the common network-visible services such as mail servers, FTP servers, and DNS servers - from accessing files which those services have no valid reason to access. This action alone prevents a huge amount of possible damage from network attacks against services, from trojaned software, and so forth.

This guide recommends that SELinux be enabled using the default (targeted) policy on every Oracle Linux 7 system, unless that system has unusual requirements which make a stronger policy appropriate. For more information on SELinux, see https://docs.oracle.com/en/operating-systems/oracle-linux/selinux/.
Group   SELinux - Booleans   Group contains 1 rule
[ref]   Enable or Disable runtime customization of SELinux system policies without having to reload or recompile the SELinux policy.

Rule   Configure the polyinstantiation_enabled SELinux Boolean   [ref]

By default, the SELinux boolean polyinstantiation_enabled is disabled. This setting should be configured to true.
To set the polyinstantiation_enabled SELinux boolean, run the following command: 
$ sudo setsebool -P polyinstantiation_enabled true
Rationale:
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sebool_polyinstantiation_enabled
Identifiers and References

References:  BP28(R39)


Complexity:low
Disruption:low
Strategy:enable
- name: XCCDF Value var_polyinstantiation_enabled # promote to variable
  set_fact:
    var_polyinstantiation_enabled: !!str true
  tags:
    - always

- name: Ensure libsemanage-python installed
  package:
    name: libsemanage-python
    state: present
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( lookup("env", "container") == "bwrap-osbuild" )
  tags:
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sebool_polyinstantiation_enabled

- name: Set SELinux boolean polyinstantiation_enabled accordingly
  seboolean:
    name: polyinstantiation_enabled
    state: '{{ var_polyinstantiation_enabled }}'
    persistent: true
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - not ( lookup("env", "container") == "bwrap-osbuild" )
  tags:
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - sebool_polyinstantiation_enabled

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if ! ( [ "${container:-}" == "bwrap-osbuild" ] ) && [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_polyinstantiation_enabled='true'


setsebool -P polyinstantiation_enabled $var_polyinstantiation_enabled

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

Rule   Ensure SELinux State is Enforcing   [ref]

The SELinux state should be set to enforcing at system boot time. In the file /etc/selinux/config, add or correct the following line to configure the system to boot into enforcing mode: 
SELINUX=enforcing
Rationale:
Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_selinux_state
Identifiers and References

References:  BP28(R4), BP28(R66), 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, CCI-001084, CCI-002165, CCI-002696, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000445-GPOS-00199, SRG-OS-000134-GPOS-00068, OL07-00-020210, SV-221716r853675_rule


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

- name: Ensure SELinux State is Enforcing
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/selinux/config
      create: false
      regexp: ^SELINUX=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: false
      regexp: ^SELINUX=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: true
      regexp: ^SELINUX=
      line: SELINUX={{ var_selinux_state }}
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-020210
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - NIST-800-53-AU-9
  - NIST-800-53-SC-7(21)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - selinux_state

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

var_selinux_state='enforcing'


if [ -e "/etc/selinux/config" ] ; then
    
    LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
else
    touch "/etc/selinux/config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/selinux/config"

cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUX=$var_selinux_state" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"

fixfiles onboot
fixfiles -f relabel

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Services   Group contains 13 groups and 19 rules
[ref]   The best protection against vulnerable software is running less software. This section describes how to review the software which Oracle Linux 7 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Oracle Linux 7 system and provides guidance about which ones can be safely disabled.

Oracle Linux 7 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Oracle Linux 7 systems, it is highly recommended to select the minimal packages and then build up the system from there.
Group   DHCP   Group contains 1 group and 1 rule
[ref]   The Dynamic Host Configuration Protocol (DHCP) allows systems to request and obtain an IP address and other configuration parameters from a server.

This guide recommends configuring networking on clients by manually editing the appropriate files under /etc/sysconfig. Use of DHCP can make client systems vulnerable to compromise by rogue DHCP servers, and should be avoided unless necessary. If using DHCP is necessary, however, there are best practices that should be followed to minimize security risk.
Group   Disable DHCP Server   Group contains 1 rule
[ref]   The DHCP server dhcpd is not installed or activated by default. If the software was installed and activated, but the system does not need to act as a DHCP server, it should be disabled and removed.

Rule   Uninstall DHCP Server Package   [ref]

If the system does not need to act as a DHCP server, the dhcp package can be uninstalled. The dhcp package can be removed with the following command: 
$ sudo yum erase dhcp
Rationale:
Removing the DHCP server ensures that it cannot be easily or accidentally reactivated and disrupt network operation.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_dhcp_removed
Identifiers and References

References:  BP28(R1), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=dhcp

Complexity:low
Disruption:low
Strategy:disable
include remove_dhcp

class remove_dhcp {
  package { 'dhcp':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure dhcp is removed
  package:
    name: dhcp
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_dhcp_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove dhcp
#	   from the system, and may remove any packages
#	   that depend on dhcp. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "dhcp" ; then

    yum remove -y "dhcp"

fi
Group   Mail Server Software   Group contains 1 group and 3 rules
[ref]   Mail servers are used to send and receive email over the network. Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious targets of network attack. Ensure that systems are not running MTAs unnecessarily, and configure needed MTAs as defensively as possible.

Very few systems at any site should be configured to directly receive email over the network. Users should instead use mail client programs to retrieve email from a central server that supports protocols such as IMAP or POP3. However, it is normal for most systems to be independently capable of sending email, for instance so that cron jobs can report output to an administrator. Most MTAs, including Postfix, support a submission-only mode in which mail can be sent from the local system to a central site MTA (or directly delivered to a local account), but the system still cannot receive mail directly over a network.

The alternatives program in Oracle Linux 7 permits selection of other mail server software (such as Sendmail), but Postfix is the default and is preferred. Postfix was coded with security in mind and can also be more effectively contained by SELinux as its modular design has resulted in separate processes performing specific actions. More information is available on its website, http://www.postfix.org.
Group   Configure SMTP For Mail Clients   Group contains 2 rules
[ref]   This section discusses settings for Postfix in a submission-only e-mail configuration.

Rule   Configure System to Forward All Mail For The Root Account   [ref]

Make sure that mails delivered to root user are forwarded to a monitored email address. Make sure that the address system.administrator@mail.mil is a valid email address reachable from the system in question. Use the following command to configure the alias: 
$ sudo echo "root: system.administrator@mail.mil" >> /etc/aliases
$ sudo newaliases
Rationale:
A number of system services utilize email messages sent to the root user to notify system administrators of active or impending issues. These messages must be forwarded to at least one monitored email address.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_postfix_client_configure_mail_alias
Identifiers and References

References:  BP28(R49), CCI-000139, CCI-000366, CM-6(a), SRG-OS-000046-GPOS-00022

Rule   Disable Postfix Network Listening   [ref]

Edit the file /etc/postfix/main.cf to ensure that only the following inet_interfaces line appears: 
inet_interfaces = loopback-only
Rationale:
This ensures postfix accepts mail messages (such as cron job reports) from the local system only, and not from the network, which protects it from network attack.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_postfix_network_listening_disabled
Identifiers and References

References:  BP28(R48), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000382, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_postfix_inet_interfaces # promote to variable
  set_fact:
    var_postfix_inet_interfaces: !!str loopback-only
  tags:
    - always

- name: Gather list of packages
  package_facts:
    manager: auto
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - ''
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - postfix_network_listening_disabled
  - restrict_strategy

- name: Make changes to Postfix configuration file
  lineinfile:
    path: /etc/postfix/main.cf
    create: false
    regexp: ^inet_interfaces\s*=\s.*
    line: inet_interfaces = {{ var_postfix_inet_interfaces }}
    state: present
    insertafter: ^inet_interfaces\s*=\s.*
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - '"postfix" in ansible_facts.packages'
  - '"postfix" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - postfix_network_listening_disabled
  - restrict_strategy


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

var_postfix_inet_interfaces='loopback-only'


if [ -e "/etc/postfix/main.cf" ] ; then
    
    LC_ALL=C sed -i "/^\s*inet_interfaces\s\+=\s\+/Id" "/etc/postfix/main.cf"
else
    touch "/etc/postfix/main.cf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/postfix/main.cf"

cp "/etc/postfix/main.cf" "/etc/postfix/main.cf.bak"
# Insert at the end of the file
printf '%s\n' "inet_interfaces=$var_postfix_inet_interfaces" >> "/etc/postfix/main.cf"
# Clean up after ourselves.
rm "/etc/postfix/main.cf.bak"

systemctl restart postfix

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

Rule   Uninstall Sendmail Package   [ref]

Sendmail is not the default mail transfer agent and is not installed by default. The sendmail package can be removed with the following command: 
$ sudo yum erase sendmail
Rationale:
The sendmail software was not developed with security in mind and its design prevents it from being effectively contained by SELinux. Postfix should be used instead.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_sendmail_removed
Identifiers and References

References:  BP28(R1), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000381, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SRG-OS-000095-GPOS-00049


Complexity:low
Disruption:low
Strategy:disable

package --remove=sendmail

Complexity:low
Disruption:low
Strategy:disable
include remove_sendmail

class remove_sendmail {
  package { 'sendmail':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure sendmail is removed
  package:
    name: sendmail
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_sendmail_removed

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

# CAUTION: This remediation script will remove sendmail
#	   from the system, and may remove any packages
#	   that depend on sendmail. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "sendmail" ; then

    yum remove -y "sendmail"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   Obsolete Services   Group contains 6 groups and 11 rules
[ref]   This section discusses a number of network-visible services which have historically caused problems for system security, and for which disabling or severely limiting the service has been the best available guidance for some time. As a result of this, many of these services are not installed as part of Oracle Linux 7 by default.

Organizations which are running these services should switch to more secure equivalents as soon as possible. If it remains absolutely necessary to run one of these services for legacy reasons, care should be taken to restrict the service as much as possible, for instance by configuring host firewall software such as iptables to restrict access to the vulnerable service to only those remote hosts which have a known need to use it.
Group   Xinetd   Group contains 1 rule
[ref]   The xinetd service acts as a dedicated listener for some network services (mostly, obsolete ones) and can be used to provide access controls and perform some logging. It has been largely obsoleted by other features, and it is not installed by default. The older Inetd service is not even available as part of Oracle Linux 7.

Rule   Uninstall xinetd Package   [ref]

The xinetd package can be removed with the following command: 
$ sudo yum erase xinetd
Rationale:
Removing the xinetd package decreases the risk of the xinetd service's accidental (or intentional) activation.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_xinetd_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000305, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=xinetd

Complexity:low
Disruption:low
Strategy:disable
include remove_xinetd

class remove_xinetd {
  package { 'xinetd':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure xinetd is removed
  package:
    name: xinetd
    state: absent
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_xinetd_removed

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

# CAUTION: This remediation script will remove xinetd
#	   from the system, and may remove any packages
#	   that depend on xinetd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "xinetd" ; then

    yum remove -y "xinetd"

fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Group   NIS   Group contains 2 rules
[ref]   The Network Information Service (NIS), also known as 'Yellow Pages' (YP), and its successor NIS+ have been made obsolete by Kerberos, LDAP, and other modern centralized authentication services. NIS should not be used because it suffers from security problems inherent in its design, such as inadequate protection of important authentication information.

Rule   Remove NIS Client   [ref]

The Network Information Service (NIS), formerly known as Yellow Pages, is a client-server directory service protocol used to distribute system configuration files. The NIS client (ypbind) was used to bind a system to an NIS server and receive the distributed configuration files.
Rationale:
The NIS service is inherently an insecure system that has been vulnerable to DOS attacks, buffer overflows and has poor authentication for querying NIS maps. NIS generally has been replaced by such protocols as Lightweight Directory Access Protocol (LDAP). It is recommended that the service be removed.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_ypbind_removed
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=ypbind

Complexity:low
Disruption:low
Strategy:disable
include remove_ypbind

class remove_ypbind {
  package { 'ypbind':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure ypbind is removed
  package:
    name: ypbind
    state: absent
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_ypbind_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove ypbind
#	   from the system, and may remove any packages
#	   that depend on ypbind. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "ypbind" ; then

    yum remove -y "ypbind"

fi

Rule   Uninstall ypserv Package   [ref]

The ypserv package can be removed with the following command: 
$ sudo yum erase ypserv
Rationale:
The NIS service provides an unencrypted authentication service which does not provide for the confidentiality and integrity of user passwords or the remote session. Removing the ypserv package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_ypserv_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, 2.2.4, SRG-OS-000095-GPOS-00049, OL07-00-020010, SV-221705r603260_rule


Complexity:low
Disruption:low
Strategy:disable

package --remove=ypserv

Complexity:low
Disruption:low
Strategy:disable
include remove_ypserv

class remove_ypserv {
  package { 'ypserv':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure ypserv is removed
  package:
    name: ypserv
    state: absent
  tags:
  - DISA-STIG-OL07-00-020010
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-IA-5(1)(c)
  - PCI-DSS-Req-2.2.2
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_ypserv_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove ypserv
#	   from the system, and may remove any packages
#	   that depend on ypserv. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "ypserv" ; then

    yum remove -y "ypserv"

fi
Group   Rlogin, Rsh, and Rexec   Group contains 2 rules
[ref]   The Berkeley r-commands are legacy services which allow cleartext remote access and have an insecure trust model.

Rule   Uninstall rsh-server Package   [ref]

The rsh-server package can be removed with the following command: 
$ sudo yum erase rsh-server
Rationale:
The rsh-server service provides unencrypted remote access service which does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. If a privileged user were to login using this service, the privileged user password could be compromised. The rsh-server package provides several obsolete and insecure network services. Removing it decreases the risk of those services' accidental (or intentional) activation.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_rsh-server_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000095-GPOS-00049, OL07-00-020000, SV-221704r603260_rule


Complexity:low
Disruption:low
Strategy:disable

package --remove=rsh-server

Complexity:low
Disruption:low
Strategy:disable
include remove_rsh-server

class remove_rsh-server {
  package { 'rsh-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure rsh-server is removed
  package:
    name: rsh-server
    state: absent
  tags:
  - DISA-STIG-OL07-00-020000
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-IA-5(1)(c)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_rsh-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove rsh-server
#	   from the system, and may remove any packages
#	   that depend on rsh-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "rsh-server" ; then

    yum remove -y "rsh-server"

fi

Rule   Uninstall rsh Package   [ref]

The rsh package contains the client commands for the rsh services
Rationale:
These legacy clients contain numerous security exposures and have been replaced with the more secure SSH package. Even if the server is removed, it is best to ensure the clients are also removed to prevent users from inadvertently attempting to use these commands and therefore exposing their credentials. Note that removing the rsh package removes the clients for rsh,rcp, and rlogin.
Severity: 
unknown
Rule ID:xccdf_org.ssgproject.content_rule_package_rsh_removed
Identifiers and References

References:  BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=rsh

Complexity:low
Disruption:low
Strategy:disable
include remove_rsh

class remove_rsh {
  package { 'rsh':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure rsh is removed
  package:
    name: rsh
    state: absent
  tags:
  - NIST-800-171-3.1.13
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_rsh_removed
  - unknown_severity

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove rsh
#	   from the system, and may remove any packages
#	   that depend on rsh. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "rsh" ; then

    yum remove -y "rsh"

fi
Group   Chat/Messaging Services   Group contains 2 rules
[ref]   The talk software makes it possible for users to send and receive messages across systems through a terminal session.

Rule   Uninstall talk-server Package   [ref]

The talk-server package can be removed with the following command: 
 $ sudo yum erase talk-server
Rationale:
The talk software presents a security risk as it uses unencrypted protocols for communications. Removing the talk-server package decreases the risk of the accidental (or intentional) activation of talk services.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_talk-server_removed
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)


Complexity:low
Disruption:low
Strategy:disable

package --remove=talk-server

Complexity:low
Disruption:low
Strategy:disable
include remove_talk-server

class remove_talk-server {
  package { 'talk-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure talk-server is removed
  package:
    name: talk-server
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_talk-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove talk-server
#	   from the system, and may remove any packages
#	   that depend on talk-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "talk-server" ; then

    yum remove -y "talk-server"

fi

Rule   Uninstall talk Package   [ref]

The talk package contains the client program for the Internet talk protocol, which allows the user to chat with other users on different systems. Talk is a communication program which copies lines from one terminal to the terminal of another user. The talk package can be removed with the following command: 
$ sudo yum erase talk
Rationale:
The talk software presents a security risk as it uses unencrypted protocols for communications. Removing the talk package decreases the risk of the accidental (or intentional) activation of talk client program.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_package_talk_removed
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=talk

Complexity:low
Disruption:low
Strategy:disable
include remove_talk

class remove_talk {
  package { 'talk':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure talk is removed
  package:
    name: talk
    state: absent
  tags:
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_talk_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove talk
#	   from the system, and may remove any packages
#	   that depend on talk. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "talk" ; then

    yum remove -y "talk"

fi
Group   Telnet   Group contains 2 rules
[ref]   The telnet protocol does not provide confidentiality or integrity for information transmitted on the network. This includes authentication information such as passwords. Organizations which use telnet should be actively working to migrate to a more secure protocol.

Rule   Uninstall telnet-server Package   [ref]

The telnet-server package can be removed with the following command: 
$ sudo yum erase telnet-server
Rationale:
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore may remain unsecure. They increase the risk to the platform by providing additional attack vectors.
The telnet service provides an unencrypted remote access service which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised.
Removing the telnet-server package decreases the risk of the telnet service's accidental (or intentional) activation.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_telnet-server_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000381, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, 2.2.4, SRG-OS-000095-GPOS-00049, OL07-00-021710, SV-221763r603260_rule


Complexity:low
Disruption:low
Strategy:disable

package --remove=telnet-server

Complexity:low
Disruption:low
Strategy:disable
include remove_telnet-server

class remove_telnet-server {
  package { 'telnet-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure telnet-server is removed
  package:
    name: telnet-server
    state: absent
  tags:
  - DISA-STIG-OL07-00-021710
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-2.2.2
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_telnet-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove telnet-server
#	   from the system, and may remove any packages
#	   that depend on telnet-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "telnet-server" ; then

    yum remove -y "telnet-server"

fi

Rule   Remove telnet Clients   [ref]

The telnet client allows users to start connections to other systems via the telnet protocol.
Rationale:
The telnet protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The ssh package provides an encrypted session and stronger security and is included in Oracle Linux 7.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_telnet_removed
Identifiers and References

References:  BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.2.4


Complexity:low
Disruption:low
Strategy:disable

package --remove=telnet

Complexity:low
Disruption:low
Strategy:disable
include remove_telnet

class remove_telnet {
  package { 'telnet':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure telnet is removed
  package:
    name: telnet
    state: absent
  tags:
  - NIST-800-171-3.1.13
  - PCI-DSSv4-2.2.4
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_telnet_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove telnet
#	   from the system, and may remove any packages
#	   that depend on telnet. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "telnet" ; then

    yum remove -y "telnet"

fi
Group   TFTP Server   Group contains 2 rules
[ref]   TFTP is a lightweight version of the FTP protocol which has traditionally been used to configure networking equipment. However, TFTP provides little security, and modern versions of networking operating systems frequently support configuration via SSH or other more secure protocols. A TFTP server should be run only if no more secure method of supporting existing equipment can be found.

Rule   Uninstall tftp-server Package   [ref]

The tftp-server package can be removed with the following command: 
 $ sudo yum erase tftp-server
Rationale:
Removing the tftp-server package decreases the risk of the accidental (or intentional) activation of tftp services.

If TFTP is required for operational support (such as transmission of router configurations), its use must be documented with the Information Systems Securty Manager (ISSM), restricted to only authorized personnel, and have access control rules established.
Severity: 
high
Rule ID:xccdf_org.ssgproject.content_rule_package_tftp-server_removed
Identifiers and References

References:  BP28(R1), 11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-000318, CCI-000366, CCI-000368, CCI-001812, CCI-001813, CCI-001814, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, OL07-00-040700, SV-221885r603260_rule


Complexity:low
Disruption:low
Strategy:disable

package --remove=tftp-server

Complexity:low
Disruption:low
Strategy:disable
include remove_tftp-server

class remove_tftp-server {
  package { 'tftp-server':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure tftp-server is removed
  package:
    name: tftp-server
    state: absent
  tags:
  - DISA-STIG-OL07-00-040700
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_tftp-server_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove tftp-server
#	   from the system, and may remove any packages
#	   that depend on tftp-server. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "tftp-server" ; then

    yum remove -y "tftp-server"

fi

Rule   Remove tftp Daemon   [ref]

Trivial File Transfer Protocol (TFTP) is a simple file transfer protocol, typically used to automatically transfer configuration or boot files between systems. TFTP does not support authentication and can be easily hacked. The package tftp is a client program that allows for connections to a tftp server.
Rationale:
It is recommended that TFTP be removed, unless there is a specific need for TFTP (such as a boot server). In that case, use extreme caution when configuring the services.
Severity: 
low
Rule ID:xccdf_org.ssgproject.content_rule_package_tftp_removed
Identifiers and References

References:  BP28(R1)


Complexity:low
Disruption:low
Strategy:disable

package --remove=tftp

Complexity:low
Disruption:low
Strategy:disable
include remove_tftp

class remove_tftp {
  package { 'tftp':
    ensure => 'purged',
  }
}

Complexity:low
Disruption:low
Strategy:disable
- name: Ensure tftp is removed
  package:
    name: tftp
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_tftp_removed

Complexity:low
Disruption:low
Strategy:disable

# CAUTION: This remediation script will remove tftp
#	   from the system, and may remove any packages
#	   that depend on tftp. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

if rpm -q --quiet "tftp" ; then

    yum remove -y "tftp"

fi
Group   SSH Server   Group contains 1 group and 4 rules
[ref]   The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, through the use of public key cryptography. The implementation included with the system is called OpenSSH, and more detailed documentation is available from its website, https://www.openssh.com. Its server program is called sshd and provided by the RPM package openssh-server.
Group   Configure OpenSSH Server if Necessary   Group contains 3 rules
[ref]   If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file /etc/ssh/sshd_config. The following recommendations can be applied to this file. See the sshd_config(5) man page for more detailed information.

Rule   Set SSH Client Alive Count Max   [ref]

The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. For SSH earlier than v8.2, a ClientAliveCountMax value of 0 causes a timeout precisely when the ClientAliveInterval is set. Starting with v8.2, a value of 0 disables the timeout functionality completely. If the option is set to a number greater than 0, then the session will be disconnected after ClientAliveInterval * ClientAliveCountMax seconds without receiving a keep alive message.
Rationale:
This ensures a user login will be terminated as soon as the ClientAliveInterval is reached.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_keepalive
Identifiers and References

References:  BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, 8.2.8, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value var_sshd_set_keepalive # promote to variable
  set_fact:
    var_sshd_set_keepalive: !!str 0
  tags:
    - always

- name: Set SSH Client Alive Count Max
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveCountMax\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveCountMax\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveCountMax\s+
      line: ClientAliveCountMax {{ var_sshd_set_keepalive }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_keepalive


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

var_sshd_set_keepalive='0'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

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

Rule   Set SSH Client Alive Interval   [ref]

SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out.

To set this timeout interval, edit the following line in /etc/ssh/sshd_config as follows: 
ClientAliveInterval 600


The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600.

If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.
Warning:  SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration.
Warning:  Following conditions may prevent the SSH session to time out:
  • Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
  • Any scp or sftp activity by the same user to the host resets the timeout.
Rationale:
Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_sshd_set_idle_timeout
Identifiers and References

References:  BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, 8.2.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175, OL07-00-040320, SV-221849r853721_rule


Complexity:low
Disruption:low
Strategy:restrict
- name: XCCDF Value sshd_idle_timeout_value # promote to variable
  set_fact:
    sshd_idle_timeout_value: !!str 600
  tags:
    - always

- name: Set SSH Client Alive Interval
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveInterval\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: false
      regexp: (?i)^\s*ClientAliveInterval\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)^\s*ClientAliveInterval\s+
      line: ClientAliveInterval {{ sshd_idle_timeout_value }}
      state: present
      insertbefore: ^[#\s]*Match
      validate: /usr/sbin/sshd -t -f %s
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - CJIS-5.5.6
  - DISA-STIG-OL07-00-040320
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_idle_timeout


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

sshd_idle_timeout_value='600'


if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert before the line matching the regex '^Match'.
line_number="$(LC_ALL=C grep -n "^Match" "/etc/ssh/sshd_config.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
    # There was no match of '^Match', insert at
    # the end of the file.
    printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" >> "/etc/ssh/sshd_config"
else
    head -n "$(( line_number - 1 ))" "/etc/ssh/sshd_config.bak" > "/etc/ssh/sshd_config"
    printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" >> "/etc/ssh/sshd_config"
    tail -n "+$(( line_number ))" "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
fi
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

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

Rule   Verify Permissions on SSH Server Private *_key Key Files   [ref]

SSH server private keys - files that match the /etc/ssh/*_key glob, have to have restricted permissions. If those files are owned by the root user and the root group, they have to have the 0600 permission or stricter. If they are owned by the root user, but by a dedicated group ssh_keys, they can have the 0640 permission or stricter.
Rationale:
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Severity: 
medium
Rule ID:xccdf_org.ssgproject.content_rule_file_permissions_sshd_private_key
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.13, 3.13.10, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-2.2.4, 2.2.6, SRG-OS-000480-GPOS-00227, OL07-00-040420, SV-221859r880579_rule


include ssh_private_key_perms

class ssh_private_key_perms {
  exec { 'sshd_priv_key':
    command => "chmod 0640 /etc/ssh/*_key",
    path    => '/bin:/usr/bin'
  }
}

Complexity:low
Disruption:low
Strategy:configure
- name: Find root:root-owned keys
  ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
    -type f -group root -perm /u+xs,g+xwrs,o+xwrt
  register: root_owned_keys
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040420
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for root:root-owned keys
  ansible.builtin.file:
    path: '{{ item }}'
    mode: u-xs,g-xwrs,o-xwrt
    state: file
  with_items:
  - '{{ root_owned_keys.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040420
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Find root:ssh_keys-owned keys
  ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
    -type f -group ssh_keys -perm /u+xs,g+xws,o+xwrt
  register: dedicated_group_owned_keys
  changed_when: false
  failed_when: false
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040420
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Set permissions for root:ssh_keys-owned keys
  ansible.builtin.file:
    path: '{{ item }}'
    mode: u-xs,g-xws,o-xwrt
    state: file
  with_items:
  - '{{ dedicated_group_owned_keys.stdout_lines }}'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-OL07-00-040420
  - NIST-800-171-3.1.13
  - NIST-800-171-3.13.10
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_sshd_private_key
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed


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

for keyfile in /etc/ssh/*_key; do
    test -f "$keyfile" || continue
    if test root:root = "$(stat -c "%U:%G" "$keyfile")"; then
    
	chmod u-xs,g-xwrs,o-xwrt "$keyfile"
    
    elif test root:ssh_keys = "$(stat -c "%U:%G" "$keyfile")"; then
	chmod u-xs,g-xws,o-xwrt "$keyfile"
    else
        echo "Key-like file '$keyfile' is owned by an unexpected user:group combination"
    fi
done

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