Verify Permissions on /etc/at.allow file

Description

If /etc/at.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/at.allow, run the command:

$ sudo chmod 0640 /etc/at.allow

Rationale

If the permissions of the at.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.

Remediation

Shell script

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

#!/bin/bash

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'kernel' 2>/dev/null | grep -q installed; then

chmod u-xs,g-xws,o-xwrt /etc/at.allow

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

Ansible playbook

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

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /etc/at.allow
  stat:
    path: /etc/at.allow
  register: file_exists
  when: '"kernel" in ansible_facts.packages'
  tags:
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/at.allow
  file:
    path: /etc/at.allow
    mode: u-xs,g-xws,o-xwrt
  when:
  - '"kernel" in ansible_facts.packages'
  - file_exists.stat is defined and file_exists.stat.exists
  tags:
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_at_allow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed