AC-14 starts from a reasonable question: what can someone do on your system before they have proven who they are? You identify those actions, and you document the reason in the security plan for the system.
800-53 binds federal systems and, through contract, some others. For everyone else it is a reference, and the exercise is useful anyway.
What it means in practice
The guidance notes that organizations may allow a limited number of actions without identification or authentication, such as visiting a public website. It also allows the answer to be "none". The control applies before login, not to actions where a user has already authenticated.
The single enhancement is AC-14.1 Necessary Uses.
Evidence to collect
- A list of unauthenticated endpoints and pages, with the rationale for each.
- The approval that signed off on the list.
- An unauthenticated scan or route listing that matches the document.
Common gaps
- Debug, health or admin endpoints reachable without login that nobody wrote down.
- A list that was accurate a year ago.
How to implement it
Export your routes, mark each as public or not, and ask for a reason on every public one. Keep that list next to your system description and refresh it when releases add endpoints.
Quick check
Can the answer to AC-14 be none?
Yes. The guidance says an organization may decide that no actions can be performed without identification and authentication.
Sources
- NIST SP 800-53 Rev 5, AC-14: https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=AC-14
- NIST OSCAL catalog of SP 800-53 Rev 5: https://raw.githubusercontent.com/usnistgov/oscal-content/main/nist.gov/SP800-53/rev5/json/NIST_SP-800-53_rev5_catalog.json
