Ubuntu 22.04 LTS must automatically exit interactive command shell user sessions after 15 minutes of inactivity.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-260554	UBTU-22-412030	SV-260554r958636_rule		Medium

Description
Terminating an idle interactive command shell user session within a short time period reduces the window of opportunity for unauthorized personnel to take control of it when left unattended in a virtual terminal or physical console.

STIG	Date
Canonical Ubuntu 22.04 LTS Security Technical Implementation Guide	2024-05-30

Details

Check Text ( C-64283r953473_chk )
Verify Ubuntu 22.04 LTS is configured to automatically exit interactive command shell user sessions after 15 minutes of inactivity or less by using the following command: $ sudo grep -E "\bTMOUT=[0-9]+" /etc/bash.bashrc /etc/profile.d/* /etc/profile.d/99-terminal_tmout.sh:TMOUT=900 If "TMOUT" is not set to "900" or less, is set to "0", is commented out, or missing, this is a finding.

Fix Text (F-64191r953474_fix)
Configure Ubuntu 22.04 LTS to exit interactive command shell user sessions after 15 minutes of inactivity. Create and/or append a custom file under "/etc/profile.d/" by using the following command: $ sudo su -c "echo TMOUT=900 >> /etc/profile.d/99-terminal_tmout.sh" This will set a timeout value of 15 minutes for all future sessions. To set the timeout for the current sessions, execute the following command over the terminal session: $ export TMOUT=900

Fix Text (F-64191r953474_fix)

Configure Ubuntu 22.04 LTS to exit interactive command shell user sessions after 15 minutes of inactivity.

Create and/or append a custom file under "/etc/profile.d/" by using the following command:

$ sudo su -c "echo TMOUT=900 >> /etc/profile.d/99-terminal_tmout.sh"

This will set a timeout value of 15 minutes for all future sessions.

To set the timeout for the current sessions, execute the following command over the terminal session:

$ export TMOUT=900