NIST SP 800-53 Rev. 5 · AC-12

Session Termination

US National Institute of Standards and Technology (NIST) · cited in 19 of our lessons

Explanation

What it asks for. User sessions must be automatically terminated after defined conditions or trigger events, such as inactivity or targeted attack responses.

In practice. Doing this well means session timeouts in applications and identity providers sized to risk, session revocation when accounts are disabled or compromised, and limits on token lifetimes. Auditors look for configured timeouts, token lifetime settings and evidence that session revocation works during incident response. Identity platforms can use continuous access evaluation to end sessions when risk changes. Remote access and privileged sessions deserve shorter limits than ordinary use.

Common gaps. Long-lived tokens and refresh tokens often survive password resets, so attackers keep access. Timeouts are set generously to reduce user friction and rarely revisited. Applications built in-house sometimes do not invalidate sessions on the server side at all.

The official text
Automatically terminate a user session after [Assignment: organization-defined conditions or trigger events]. Discussion: Session termination addresses the termination of user-initiated logical sessions (in contrast to [SC-10](#sc-10) , which addresses the termination of network connections associated with communications sessions (i.e., network disconnect)). A logical session (for local, network, and remote access) is initiated whenever a user (or process acting on behalf of a user) accesses an organizational system. Such user sessions can be terminated without terminating network sessions. Session termination ends all processes associated with a user’s logical session except for those processes that are specifically created by the user (i.e., session owner) to continue after the session is terminated. Conditions or trigger events that require automatic termination of the session include organization-defined periods of user inactivity, targeted responses to certain types of incidents, or time-of-day restrictions on system use.

From NIST SP 800-53 Rev. 5, a work of the US government in the public domain.

Lessons that cite it

Real incidents where this item mattered: the latest 12 of 19.