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AC-4(6) AC · Access Control

Metadata

LOW MODERATE HIGH
1 Overlay 2 Related Controls
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Requirements NIST SOURCE

Enforce information flow control based on [metadata].

Discussion (NIST Supplemental Guidance)

Metadata is information that describes the characteristics of data. Metadata can include structural metadata describing data structures or descriptive metadata describing data content. Enforcement of allowed information flows based on metadata enables simpler and more effective flow control. Organizations consider the trustworthiness of metadata regarding data accuracy (i.e., knowledge that the metadata values are correct with respect to the data), data integrity (i.e., protecting against unauthorized changes to metadata tags), and the binding of metadata to the data payload (i.e., employing sufficiently strong binding techniques with appropriate assurance).

Implementation Guidance

Engineering Interpretation

Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.

No engineering interpretation has been authored for AC-4(6) yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.

Assessment

NIST SP 800-53A REV 5.2.0

Assessment Objectives

  1. metadata on which to base enforcement of information flow control is defined;
  2. information flow control enforcement is based on <AC-04(06)_ODP metadata>.

Examine

[SELECT FROM: Access control policy; information flow control policies; procedures addressing information flow enforcement; system design documentation; system configuration settings and associated documentation; types of metadata used to enforce information flow control decisions; system audit records; system security plan; other relevant documents or records].

Interview

[SELECT FROM: System/network administrators; organizational personnel with information security responsibilities; system developers].

Test

[SELECT FROM: Mechanisms implementing information flow enforcement policy].

Overlays

Showing the OT/ICS overlay for the parent control AC-4 — see the AC-4(6) entries within each baseline below.

OT/ICS Overlay SP 800-82r3

NIST SP 800-82r3 Appendix F, Table 22. Blank baseline means the control/control enhancement is not selected in that initial OT baseline.

LOW

Not applicable at this tier.

MODERATE

  • Base control: Included (matches standard baseline)

HIGH

  • Base control: Included (matches standard baseline)
  • Included: (4)

STIGs & CCIs

No STIG checks or CCI mappings are currently loaded for AC-4(6). This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.

Learn more about STIG/CCI integration →

Evidence

Potential Evidence — Derived

Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.

Policy

  • Access control policy
  • information flow control policies
  • system security plan

Configuration

  • system design documentation
  • system configuration settings and associated documentation

Testing

  • Mechanisms implementing information flow enforcement policy

Other Records

  • procedures addressing information flow enforcement
  • types of metadata used to enforce information flow control decisions
  • system audit records
  • other relevant documents or records