Information
The operating system must be configured so that all network connections associated with a communication session are terminated at the end of the session or after 10 minutes of inactivity from the user at a command prompt, except to fulfill documented and validated mission requirements.
Rationale:
Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element.
Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session.
Solution
Configure the operating system to terminate all network connections associated with a communications session at the end of the session or after a period of inactivity.
Create a script to enforce the inactivity timeout (for example /etc/profile.d/tmout.sh) such as:
Example: vim /etc/profile.d/tmout.sh
Add the following lines to the script.
#!/bin/bash
TMOUT=600
readonly TMOUT
export TMOUT
Notes:
This Benchmark recommendation maps to:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide:
Version 2, Release: 3 Benchmark Date: 26 Apr 2019
Vul ID: V-72223
Rule ID: SV-86847r4_rule
STIG ID: RHEL-07-040160
Severity: CAT II