BaselineWatch
Desk
Your fleet and your work Fleetyour releases and the hardware they run onTriagewhat needs a decisionWatchlistthe products and platforms you runSaved searchesthe lists you come back to
This instance Sourceswhat is read, how often, under what termsDigestthe daily or weekly summary, and alerts
How it is drawn Appearancethe look and the colour schemeBrandingthe mark this instance wears
Owner sign-in

UBTU-24-200060 Ubuntu 24.04 LTS must automatically terminate a user session after inactivity timeouts have expired.

DISA STIG library V1R7
All changes in this version
first version loaded CAT II

Maps to AC-12 via CCI-002361

Title

Ubuntu 24.04 LTS must automatically terminate a user session after inactivity timeouts have expired.

Control

Verify Ubuntu 24.04 LTS automatically terminates a user session after inactivity timeouts have expired with the following command: $ sudo grep -E "\bTMOUT=[0-9]+" /etc/bash.bashrc /etc/profile.d/* /etc/profile.d/99-terminal_tmout.sh:TMOUT=600 If "TMOUT" is not set, or if the value is "0" or is commented out, this is a finding.

Discussion

Automatic session termination addresses the termination of user-initiated logical sessions in contrast to the termination of network connections associated with communications sessions (i.e., network disconnect). A logical session (for local, network, and remote access) is initiated whenever a user (or process acting on behalf of a user) accesses an organizational information system. Such user sessions can be terminated (and thus terminate user access) without terminating network sessions. Session termination terminates all processes associated with a user's logical session except those processes specifically created by the user (i.e., session owner) to continue after the session is terminated. Conditions or trigger events requiring automatic session termination can include, for example, organization-defined periods of user inactivity, targeted responses to certain types of incidents, and time-of-day restrictions on information system use. This capability is typically reserved for specific operating system functionality where the system owner, data owner, or organization requires additional assurance.

Related controls

CCI-002361

Fix

Configure Ubuntu 24.04 LTS to automatically terminate a user session after inactivity timeouts have expired or at shutdown. Create the file "/etc/profile.d/99-terminal_tmout.sh" file if it does not exist. Modify or append the following line in the "/etc/profile.d/99-terminal_tmout.sh " file: TMOUT=600 This will set a timeout value of 10 minutes for all future sessions. To set the timeout for the current sessions, execute the following command over the terminal session: $ export TMOUT=600