Verify User Who Owns /var/log/messages File

Description

To properly set the owner of /var/log/messages, run the command:

$ sudo chown root /var/log/messages

Rationale

The /var/log/messages file contains logs of error messages in the system and should only be accessed by authorized personnel.

Remediation

Shell script

The following script can be run on the host to remediate the issue.

#!/bin/bash

newown=""
if id "0" >/dev/null 2>&1; then
  newown="0"
fi

if [[ -z "$newown" ]]; then
  >&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/var/log/messages" | grep -E -w -q "0"; then
    chown --no-dereference "$newown" /var/log/messages
fi

fi

Ansible playbook

The following playbook can be run with Ansible to remediate the issue.

- name: Set the file_owner_var_log_messages_newown variable if represented by uid
  ansible.builtin.set_fact:
    file_owner_var_log_messages_newown: '0'
  tags:
  - configure_strategy
  - file_owner_var_log_messages
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /var/log/messages
  ansible.builtin.stat:
    path: /var/log/messages
  register: file_exists
  tags:
  - configure_strategy
  - file_owner_var_log_messages
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner on /var/log/messages
  ansible.builtin.file:
    path: /var/log/messages
    follow: false
    owner: '{{ file_owner_var_log_messages_newown }}'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - configure_strategy
  - file_owner_var_log_messages
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed