UCF STIG Viewer Logo

The Ubuntu operating system must disable the x86 Ctrl-Alt-Delete key sequence.


Finding ID Version Rule ID IA Controls Severity
V-238380 UBTU-20-010460 SV-238380r654315_rule High
A locally logged-on user who presses Ctrl-Alt-Delete, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.
Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide 2021-11-19


Check Text ( C-41590r654313_chk )
Verify the Ubuntu operating system is not configured to reboot the system when Ctrl-Alt-Delete is pressed.

Check that the "ctrl-alt-del.target" (otherwise also known as reboot.target) is not active with the following command:

# systemctl status ctrl-alt-del.target
reboot.target - Reboot
Loaded: loaded (/usr/lib/systemd/system/reboot.target; disabled)
Active: inactive (dead)
Docs: man:systemd.special(7)

If the "ctrl-alt-del.target" is active, this is a finding.
Fix Text (F-41549r654314_fix)
Configure the system to disable the Ctrl-Alt-Delete sequence for the command line with the following command:

# sudo systemctl mask ctrl-alt-del.target

Reload the daemon to take effect:

# sudo systemctl daemon-reload