NIST SP 800-53 Rev. 5 AU-13 — Monitoring For Information Disclosure

What this control requires

Monitors defined open-source or information sites periodically for unauthorized disclosure, notifying personnel and taking defined actions upon discovery. This control supports the Information Disclosure Monitor capability within the Audit and Accountability family.

In plain English

Monitors defined open-source or information sites periodically for unauthorized disclosure, notifying personnel and taking defined actions upon discovery. In practice, this means you can prove you policy management-level controls on a defined cadence.

Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within Audit and Accountability, the assessor will trace your implementation back to the catalogue reference (Control AU-13) and look for objective evidence on the latest two assessment cycles.

How to implement

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

• Policy. Document the trigger, the owner and the cadence.
• Audit. Document the trigger, the owner and the cadence.
• Information. Document the trigger, the owner and the cadence.
• Monitor. Document the trigger, the owner and the cadence.
• Unauthorized. Document the trigger, the owner and the cadence.
• Scope: management, actions, information, personnel, source, information disclosure, monitor, capability.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Monitoring For Information Disclosure.

Common pitfalls

• Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• HIPAA (45 CFR Part 164) 164.512(k)(6) — Uses and disclosures for specialized government functions - Providing public benefits
• ISO/IEC 27001:2022 A.6.6 — Confidentiality or non-disclosure agreements
• SOC 2 (2017 TSC) CC4.1 — Control Monitoring
• NIST SP 800-171 Rev. 3 3.3.4 — Response to Audit Logging Process Failures

Related controls in NIST SP 800-53 Rev. 5

• Control AU-13(2) — Review Of Monitored Sites
• Control AU-14(3) — Remote Viewing And Listening
• Control AU-13(1) — Use Of Automated Tools
• Control AU-13(3) — Unauthorized Replication Of Information
• Control AU-14(1) — System Start-Up
• Control AU-10 — Non-Repudiation

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control AU-13

Topics: governance riskcontinuous monitoringpolicy management