Details

A session time-out 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. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user’s session has idled and take action to initiate the session lock.

The session lock is implemented at the point where session activity can be determined and/or controlled.

Solution

Configure the operating system to initiate a screensaver after a 15-minute period of inactivity for graphical user interfaces.

Create a database to contain the system-wide 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

You must include the ‘uint32’ along with the integer key values as shown.

Update the system databases:

# dconf update

Users must log out and back in again before the system-wide settings take effect.

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_7_V3R5_STIG.ziphttps://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_7_V3R5_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system Unix.

References

• 800-53|AC-11a.
• CAT|II
• CCI|CCI-000057
• Rule-ID|SV-204398r603261_rule
• STIG-ID|RHEL-07-010070
• STIG-Legacy|SV-86517
• STIG-Legacy|V-71893
• Vuln-ID|V-204398

Source

• Tenable.com/audits