Vulnerability Discussion

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.

Satisfies: SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010

Check

Verify RHEL 9 is configured to exit interactive command shell user sessions after 15 minutes of inactivity or less with the following command:

$ sudo grep -i tmout /etc/profile /etc/profile.d/*.sh

/etc/profile.d/tmout.sh:declare -xr TMOUT=900

If "TMOUT" is not set to "900" or less in a script located in the "/etc/'profile.d/ directory, is missing or is commented out, this is a finding.

Fix

Configure RHEL 9 to exit interactive command shell user sessions after 15 minutes of inactivity.

Add or edit the following line in "/etc/profile.d/tmout.sh":

#!/bin/bash

declare -xr TMOUT=900