Details

A session lock is a temporary network device- or administrator-initiated action taken when the administrator stops work but does not log out of the SSH session. Rather than relying on the user to manually lock their management session prior to vacating the vicinity, network devices need to be able to identify when a management session has idled and take action to initiate the session lock. Once invoked, the session lock shall remain in place until the administrator re-authenticates. No other system activity aside from re-authentication shall unlock the management session.

Solution

1. Log in to tmsh by typing the following command:

tmsh

2. To configure an automatic logout idle time for SSH sessions, use the following command syntax:

modify /sys sshd inactivity-timeout

3. For example, to configure a 15-minute automatic logout idle time, type the following command:

modify /sys sshd inactivity-timeout 900

4. Save the change by typing the following command:

save /sys config

Supportive Information

The following resource is also helpful.

• https://support.f5.com/csp/article/K53108777#link_01

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 F5.

References

• 800-53|AC-11a.
• CAT|II
• CCI|CCI-000057
• Rule-ID|SV-74523r2_rule
• STIG-ID|F5BI-DM-000007
• Vuln-ID|V-60093

Source

• Tenable.com/audits