Description
cron runs the jobs in /etc/crontab, /etc/cron.d/, the /etc/cron.hourly to
/etc/cron.monthly directories and the users' crontabs. When the package is installed,
cron.service must be enabled and running.
Ubuntu installs and enables cron by default, on servers, desktops and cloud images. The control is not applicable only when the package was removed.
Rationale
Packages and administrators rely on cron for periodic tasks: integrity checks, report mails, cleanup jobs. A stopped daemon disables them without any error message.
Impact
None known.
Applies when
Detected: when: cron is installed A scanner reports the control not applicable when one is false.
Audit
systemctl is-enabled cron must print enabled and systemctl is-active cron must print
active.
Automated: every check must pass. Scanners report each check by its id.
enabled
cron is enabled.
unit: cron.service
state: enabled
active
cron is running.
script: systemctl is-active cron.service || exit 1
Remediation
Run systemctl unmask cron if it is masked, then systemctl enable --now cron.
| Restart | none |
| Disruption | none |
Rollback
Run systemctl disable --now cron.
enabled
Generated from check enabled: the engine writes the fix for every output, it sets the expected value and the check runs again after.
Each release turns these fixes into remediate.sh and an Ansible role per profile: dry run by default, a fix runs only when its check fails.
References
- cron(8), Ubuntu manual pages Canonical, vendor-doc, accessed 2026-10-19
- systemctl(1), Ubuntu manual pages Canonical, vendor-doc, accessed 2026-10-19
Mappings
| Framework | ID | Relation |
|---|---|---|
| NIST SP 800-53 Rev. 55.1.1 | CM-6 | related |
How this control relates to the other framework's: equivalent, stricter, looser, partial or related.
Related controls
- related
CB-UBU-SVC-018Restrict the system crontab and cron directories to root
People and lifecycle
| Authors |
|
| Verified | 2026-10-19 by Sn0wAlice on 20.04, Proxmox VM, Ubuntu 20.04 cloud image, kernel 5.4.0-216-generic. Passes on the stock image (cron installed and running) and after reboot. |
| Verified | 2026-10-19 by Sn0wAlice on 22.04, Proxmox VM, Ubuntu 22.04 cloud image, kernel 5.15.0-198-generic. Passes on the stock image (cron installed and running) and after reboot. |
| Verified | 2026-10-19 by Sn0wAlice on 24.04, Proxmox VM, Ubuntu 24.04 cloud image, kernel 6.8.0-147-generic. Passes on the stock image (cron installed and running) and after reboot. |
| Verified | 2026-10-19 by Sn0wAlice on 26.04, Proxmox VM, Ubuntu 26.04 cloud image, kernel 7.0.0-38-generic. Passes on the stock image (cron installed and running) and after reboot. |
| Introduced in | v0.1.0 |
| Created, updated | 2026-10-19, 2026-10-19 |
| Translations | fr |
