AlmaLinux OS 9 must automatically lock graphical user sessions after 15 minutes of inactivity.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-269103	SRG-OS-000031-GPOS-00012	ALMA-09-001120	SV-269103r1049985_rule	2025-02-20	1

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 log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information.

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 log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information.

ℹ️ Check
Note: This requirement assumes the use of the AlmaLinux OS 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify AlmaLinux OS 9 initiates a session lock after a 10-minute period of inactivity for graphical user interfaces with the following command: $ gsettings get org.gnome.desktop.session idle-delay uint32 900 If "idle-delay" is set to "0" or a value greater than "900", this is a finding.

ℹ️ Check

Note: This requirement assumes the use of the AlmaLinux OS 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Verify AlmaLinux OS 9 initiates a session lock after a 10-minute period of inactivity for graphical user interfaces with the following command: $ gsettings get org.gnome.desktop.session idle-delay uint32 900 If "idle-delay" is set to "0" or a value greater than "900", this is a finding.

✔️ Fix
Configure AlmaLinux OS 9 to initiate a screensaver after a 10-minute period of inactivity for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) with the following command: $ touch /etc/dconf/db/local.d/00-screensaver Edit /etc/dconf/db/local.d/00-screensaver and add or update the following lines: [org/gnome/desktop/session] # Set the lock time out to 900 seconds before the session is considered idle idle-delay=uint32 900 Update the system databases: $ dconf update

✔️ Fix

Configure AlmaLinux OS 9 to initiate a screensaver after a 10-minute period of inactivity for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) with the following command: $ touch /etc/dconf/db/local.d/00-screensaver Edit /etc/dconf/db/local.d/00-screensaver and add or update the following lines: [org/gnome/desktop/session] # Set the lock time out to 900 seconds before the session is considered idle idle-delay=uint32 900 Update the system databases: $ dconf update