Limit Password Reuse: password-auth

An XCCDF Rule

Description

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

On systems with newer versions of authselect, the pam_pwhistory PAM module can be enabled via authselect feature:

authselect enable-feature with-pwhistory

Otherwise, it should be enabled using an authselect custom profile.

Newer systems also have the /etc/security/pwhistory.conf file for setting pam_pwhistory module options. This file should be used whenever available. Otherwise, the pam_pwhistory module options can be set in PAM files.

The value for remember option must be equal or greater than

warning alert: 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 alert: 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. If a custom profile was created and used in the system before this authselect feature was available, the new feature can't be used with this custom profile and the remediation will fail. In this case, the custom profile should be recreated or manually updated.

Rationale

Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.

ID: xccdf_org.ssgproject.content_rule_accounts_password_pam_pwhistory_remember_password_auth
Severity: Medium
References: 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(1)(e) IA-5(f)

PR.AC-1 PR.AC-6 PR.AC-7

Req-8.2.5

SRG-OS-000077-GPOS-00045

8.3 8.3.7
Updated: about 1 month ago

Remediation Templates

# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then
var_password_pam_remember='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_password_pam_remember" use="legacy"/>'
var_password_pam_remember_control_flag='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_password_pam_remember_control_flag" use="legacy"/>'

var_password_pam_remember_control_flag="$(echo $var_password_pam_remember_control_flag | cut -d \, -f 1)"

if [ -f /usr/bin/authselect ]; then
    if authselect list-features sssd | 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=$(basename "/etc/pam.d/password-auth")
        PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

        authselect apply-changes -b
        if ! grep -qP "^\s*password\s+$var_password_pam_remember_control_flag\s+pam_pwhistory.so\s*.*" "$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$var_password_pam_remember_control_flag \2/" "$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     $var_password_pam_remember_control_flag    pam_pwhistory.so" "$PAM_FILE_PATH"
                else
                    echo "password    $var_password_pam_remember_control_flag    pam_pwhistory.so" >> "$PAM_FILE_PATH"
                fi
            fi
        fi
    fi
else
    if ! grep -qP "^\s*password\s+$var_password_pam_remember_control_flag\s+pam_pwhistory.so\s*.*" "/etc/pam.d/password-auth"; then
        # Line matching group + control + module was not found. Check group + module.
        if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "/etc/pam.d/password-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$var_password_pam_remember_control_flag \2/" "/etc/pam.d/password-auth"
        else
            LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "/etc/pam.d/password-auth" | tail -n 1 | cut -d: -f 1)
            if [ ! -z $LAST_MATCH_LINE ]; then
                sed -i --follow-symlinks $LAST_MATCH_LINE" a password     $var_password_pam_remember_control_flag    pam_pwhistory.so" "/etc/pam.d/password-auth"
            else
                echo "password    $var_password_pam_remember_control_flag    pam_pwhistory.so" >> "/etc/pam.d/password-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_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_remember"'|g' $PWHISTORY_CONF
    fi
    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.*\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/password-auth was not found" >&2
    fi
else
    PAM_FILE_PATH="/etc/pam.d/password-auth"
    if [ -f /usr/bin/authselect ]; then
        
        if ! authselect check; then
        echo "
        authselect integrity check failed. Remediation aborted!
        This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
        It is not recommended to manually edit the PAM files when authselect tool is available.
        In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
        exit 1
        fi

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

        authselect apply-changes -b
    fi
    if ! grep -qP "^\s*password\s+requisite\s+pam_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*' "$PAM_FILE_PATH")" -eq 1 ]; then
            # The control is updated only if one single line matches.
            sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1requisite \2/" "$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_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_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

- 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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
- name: XCCDF Value var_password_pam_remember # promote to variable
  set_fact:
    var_password_pam_remember: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_password_pam_remember" use="legacy"/>
  tags:
    - always
- name: XCCDF Value var_password_pam_remember_control_flag # promote to variable
  set_fact:
    var_password_pam_remember_control_flag: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_password_pam_remember_control_flag" use="legacy"/>
  tags:
    - always
- name: 'Limit Password Reuse: password-auth - 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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: 'Limit Password Reuse: password-auth - Collect the available authselect features'
  ansible.builtin.command:
    cmd: authselect list-features sssd
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

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

  - name: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: password-auth - 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: password-auth - 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: password-auth - 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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

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

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

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

    - name: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: password-auth - Define a fact for control already
      filtered in case filters are used'
    ansible.builtin.set_fact:
      pam_module_control: '{{ var_password_pam_remember_control_flag.split(",")[0]
        }}'

  - name: 'Limit Password Reuse: 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+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

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

    - name: 'Limit Password Reuse: 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_pwhistory.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: 'Limit Password Reuse: 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_pwhistory.so.*)
        replace: \1{{ pam_module_control }} \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: 'Limit Password Reuse: password-auth - 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    {{ pam_module_control }}    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: 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
  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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

- name: 'Limit Password Reuse: password-auth - 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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

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

  - name: 'Limit Password Reuse: password-auth - 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_remember }}
      state: present

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

    - name: 'Limit Password Reuse: 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

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

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

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

        - name: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: password-auth - Define a fact for control already
          filtered in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: ''

      - name: 'Limit Password Reuse: password-auth - 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: password-auth - 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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

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

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

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

    - name: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: 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: 'Limit Password Reuse: password-auth - Define a fact for control already
      filtered in case filters are used'
    ansible.builtin.set_fact:
      pam_module_control: requisite

  - name: 'Limit Password Reuse: 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+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_line_present

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

    - name: 'Limit Password Reuse: 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_pwhistory.so\s*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_other_control_present

    - name: 'Limit Password Reuse: 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_pwhistory.so.*)
        replace: \1{{ pam_module_control }} \2
      register: result_pam_module_edit
      when:
      - result_pam_line_other_control_present.found == 1

    - name: 'Limit Password Reuse: password-auth - Ensure the required PAM module
        line is included in {{ pam_file_path }}'
      ansible.builtin.lineinfile:
        dest: '{{ pam_file_path }}'
        line: password    {{ pam_module_control }}    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: 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: 'Limit Password Reuse: password-auth - Define a fact for control already
      filtered in case filters are used'
    ansible.builtin.set_fact:
      pam_module_control: requisite

  - name: 'Limit Password Reuse: 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+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*\sremember\b
      state: absent
    check_mode: true
    changed_when: false
    register: result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present

  - name: 'Limit Password Reuse: password-auth - 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+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so.*)
      line: \1 remember={{ var_password_pam_remember }}
      state: present
    register: result_pam_accounts_password_pam_pwhistory_remember_password_auth_add
    when:
    - result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present.found
      == 0

  - name: 'Limit Password Reuse: password-auth - 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+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s+.*)(remember)=[0-9a-zA-Z]+\s*(.*)
      line: \1\2={{ var_password_pam_remember }} \3
    register: result_pam_accounts_password_pam_pwhistory_remember_password_auth_edit
    when:
    - result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present.found
      > 0

  - name: 'Limit Password Reuse: password-auth - 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
  - PCI-DSSv4-8.3.7
  - accounts_password_pam_pwhistory_remember_password_auth
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed

Limit Password Reuse: password-auth

Description

Rationale

Remediation Templates

A Shell Script

An Ansible Snippet