Ubuntu 22.04 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-260539	UBTU-22-271030	SV-260539r953430_rule		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.

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 22.04 LTS Security Technical Implementation Guide	2024-03-21

Details

Check Text ( C-64268r953428_chk )
Verify Ubuntu 22.04 LTS is not configured to reboot the system when Ctrl-Alt-Delete is pressed when using a graphical user interface by using the following command: Note: If no graphical user interface is installed, this requirement is not applicable. $ 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.

Check Text ( C-64268r953428_chk )

Verify Ubuntu 22.04 LTS is not configured to reboot the system when Ctrl-Alt-Delete is pressed when using a graphical user interface by using the following command:

Note: If no graphical user interface is installed, this requirement is not applicable.

$ 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-64176r953429_fix)
Configure Ubuntu 22.04 LTS to disable the Ctrl-Alt-Delete sequence when using a graphical user interface. $ gsettings set org.gnome.settings-daemon.plugins.media-keys logout [] Update the dconf settings: # dconf update