Ubuntu 24.04 LTS must disable the x86 Ctrl-Alt-Delete key sequence if a graphical user interface is installed.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-270711 | UBTU-24-300025 | SV-270711r1184069_rule | CCI-000366 | high |
| Description | ||||
| 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. In the graphical environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken. | ||||
| STIG | Date | |||
| Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide | 2026-02-06 | |||
Details
Check Text (C-270711r1184069_chk)
Verify Ubuntu 24.04 LTS is not configured to reboot the system when Ctrl-Alt-Delete is pressed when using a graphical user interface with the following command:
$ gsettings get org.gnome.settings-daemon.plugins.media-keys logout
@as []
If the "logout" key is bound to an action, is commented out, or is missing, this is a finding.
Fix Text (F-74645r1184068_fix)
Configure Ubuntu 24.04 LTS to disable the Ctrl-Alt-Delete sequence when using a graphical user interface.
Create or edit a file named /etc/dconf/db/local.d/00-mediakeys with the following contents:
[org/gnome/settings-daemon/plugins/media-keys]
logout=@as []
Update the dconf settings:
$ sudo dconf update