- Set idle timeouts on the paths that matter most first: remote access, administrative sessions, and connections into CUI systems.
- Record the defined inactivity period per connection type — the parameter is yours to set and the assessor's to test.
03.13.09OFFICIAL TITLEPENDING NIST SME REVIEW
03.13.09 — Network Disconnect
03.13 System and Communications Protection · NIST SP 800-171 Rev. 3
Independent summary of the official requirement
Requires terminating network connections associated with communications sessions at the end of the sessions or after an organization-defined period of inactivity.
Rev. 3 requirement text is multi-part and parameterized with organization-defined values, so this site summarizes rather than reproduces it. The summary is independent — read the official publication for the binding wording.
NIST SP 800-171 Rev. 3 — Protecting CUI in Nonfederal Systems ↗NIST SP 800-171A Rev. 3 — Assessing Security Requirements for CUI ↗Independent interpretation
What this requirement is after
Sessions that outlive their use are standing attack surface: the idle VPN tunnel, the forgotten administrative session, the connection held open overnight. Connections terminate when the session ends or after a defined idle period, so access has to be re-earned rather than inherited from yesterday.
Mapped practices
Brilliant at the Basics practices that support this requirement
No practice maps to this requirement — deliberately.
The campaign’s twenty practices are a priority list, not a control catalog, and none of them works this requirement’s substance directly. It still applies to you if it is in your contract’s scope: address it through your own implementation and the related artifacts below, and treat the absence of a mapping here as honesty, not permission to skip it.
Doing the work
Implementation considerations and evidence
- Timeout configurations for VPN, remote desktop, and administrative access paths
- The written inactivity parameters and a sampled check that sessions actually terminate
Artifacts
Templates and worksheets with a mapped relationship
No artifact in the library names this requirement yet. The library index groups everything by category and practice.
The other revision
Where this came from in Rev. 2
Provenance
Sources and review status
| Primary sources | NIST SP 800-171 Rev. 3 — Protecting CUI in Nonfederal Systems · NIST SP 800-171A Rev. 3 — Assessing Security Requirements for CUI |
|---|---|
| Review status | Pending NIST SME review |
| Content version | 1.0 |
| Updated |