-w /etc/sudoers.d/ -p wa -k actions

-w /etc/sudoers.d/ -p wa -k actions

#!/bin/bash

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && dpkg-query --show --showformat='${db:Status-Status}\n' 'auditd' 2>/dev/null | grep -q installed; then

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


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

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

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

# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers.d/" /etc/audit/rules.d/*.rules)

# For each of the matched entries
for match in "${matches[@]}"
do
    # Extract filepath from the match
    rulesd_audit_file=$(echo $match | cut -f1 -d ':')
    # Append that path into list of files for inspection
    files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
    # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
    key_rule_file="/etc/audit/rules.d/actions.rules"
    # If the actions.rules file doesn't exist yet, create it with correct permissions
    if [ ! -e "$key_rule_file" ]
    then
        touch "$key_rule_file"
        chmod 0640 "$key_rule_file"
    fi
    files_to_inspect+=("$key_rule_file")
fi

# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
    # Check if audit watch file system object rule for given path already present
    if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
    then
        # Rule is found => verify yet if existing rule definition contains
        # all of the required access type bits

        # Define BRE whitespace class shortcut
        sp="[[:space:]]"
        # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
        current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
        # Split required access bits string into characters array
        # (to check bit's presence for one bit at a time)
        for access_bit in $(echo "wa" | grep -o .)
        do
            # For each from the required access bits (e.g. 'w', 'a') check
            # if they are already present in current access bits for rule.
            # If not, append that bit at the end
            if ! grep -q "$access_bit" <<< "$current_access_bits"
            then
                # Concatenate the existing mask with the missing bit
                current_access_bits="$current_access_bits$access_bit"
            fi
        done
        # Propagate the updated rule's access bits (original + the required
        # ones) back into the /etc/audit/audit.rules file for that rule
        sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
    else
        # Rule isn't present yet. Append it at the end of $audit_rules_file file
        # with proper key

        echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
    fi
done

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

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers.d/ already exists in /etc/audit/rules.d/
  find:
    paths: /etc/audit/rules.d
    contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
    patterns: '*.rules'
  register: find_existing_watch_rules_d
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Search /etc/audit/rules.d for other rules with specified key actions
  find:
    paths: /etc/audit/rules.d
    contains: ^.*(?:-F key=|-k\s+)actions$
    patterns: '*.rules'
  register: find_watch_key
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use /etc/audit/rules.d/actions.rules as the recipient for the rule
  set_fact:
    all_files:
    - /etc/audit/rules.d/actions.rules
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Use matched file as the recipient for the rule
  set_fact:
    all_files:
    - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
    is defined and find_existing_watch_rules_d.matched == 0
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers.d/ in /etc/audit/rules.d/
  lineinfile:
    path: '{{ all_files[0] }}'
    line: -w /etc/sudoers.d/ -p wa -k actions
    create: true
    mode: '0640'
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
    == 0
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Check if watch rule for /etc/sudoers.d/ already exists in /etc/audit/audit.rules
  find:
    paths: /etc/audit/
    contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
    patterns: audit.rules
  register: find_existing_watch_audit_rules
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Add watch rule for /etc/sudoers.d/ in /etc/audit/audit.rules
  lineinfile:
    line: -w /etc/sudoers.d/ -p wa -k actions
    state: present
    dest: /etc/audit/audit.rules
    create: true
    mode: '0640'
  when:
  - '"auditd" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
    == 0
  tags:
  - DISA-STIG-UBTU-22-654225
  - audit_rules_sudoers_d
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy