Ubuntu 22.04 LTS must initiate a graphical session lock after 15 minutes of inactivity.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-260538	SRG-OS-000029-GPOS-00010	UBTU-22-271025	SV-260538r1069119_rule	2025-03-03	2

Description
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, a session lock of Ubuntu 22.04 LTS must remain in place until the user reauthenticates. No other activity aside from reauthentication must unlock the system.

Description

A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, a session lock of Ubuntu 22.04 LTS must remain in place until the user reauthenticates. No other activity aside from reauthentication must unlock the system.

ℹ️ Check
Verify Ubuntu 22.04 LTS has a graphical user interface session lock configured to activate after 15 minutes of inactivity by using the following commands: Note: If no graphical user interface is installed, this requirement is not applicable. Get the following settings to verify the graphical user interface session is configured to lock the graphical user session after 15 minutes of inactivity: $ gsettings get org.gnome.desktop.screensaver lock-enabled true $ gsettings get org.gnome.desktop.screensaver lock-delay uint32 0 $ gsettings get org.gnome.desktop.session idle-delay uint32 900 If "lock-enabled" is not set to "true", is commented out, or is missing, this is a finding. If "lock-delay" is set to a value greater than "0", or if "idle-delay" is set to a value greater than "900", is commented out, or is missing, this is a finding.

ℹ️ Check

Verify Ubuntu 22.04 LTS has a graphical user interface session lock configured to activate after 15 minutes of inactivity by using the following commands: Note: If no graphical user interface is installed, this requirement is not applicable. Get the following settings to verify the graphical user interface session is configured to lock the graphical user session after 15 minutes of inactivity: $ gsettings get org.gnome.desktop.screensaver lock-enabled true $ gsettings get org.gnome.desktop.screensaver lock-delay uint32 0 $ gsettings get org.gnome.desktop.session idle-delay uint32 900 If "lock-enabled" is not set to "true", is commented out, or is missing, this is a finding. If "lock-delay" is set to a value greater than "0", or if "idle-delay" is set to a value greater than "900", is commented out, or is missing, this is a finding.

✔️ Fix
Configure Ubuntu 22.04 LTS to lock the current graphical user interface session after 15 minutes of inactivity. Create or edit a file named /etc/dconf/db/local.d/00-screensaver with the following contents: [org/gnome/desktop/screensaver] lock-enabled=true lock-delay=0 [org/gnome/desktop/session] idle-delay=600