Ensure that /etc/cron.allow exists

Cette page n'est pas encore disponible en français, sa traduction est en cours.
Si vous avez des questions ou des retours sur notre projet de traduction actuel, n'hésitez pas à nous contacter.

Description

The file /etc/cron.allow should exist and should be used instead of /etc/cron.deny.

Rationale

Access to crontab should be restricted. It is easier to manage an allow list than a deny list. Therefore, /etc/cron.allow needs to be created and used instead of /etc/cron.deny. Regardless of the existence of any of these files, the root administrative user is always allowed to setup a crontab.

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='${db:Status-Status}' 'linux-base' 2>/dev/null | grep -q '^installed$'; then

touch /etc/cron.allow
    chown 0 /etc/cron.allow
    chmod 0600 /etc/cron.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:
  - disable_strategy
  - file_cron_allow_exists
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Add empty /etc/cron.allow
  file:
    path: /etc/cron.allow
    state: touch
    owner: '0'
    mode: '0600'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - disable_strategy
  - file_cron_allow_exists
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed