Security requirement
Mark system media that contain CUI to indicate distribution limitations, handling caveats, and applicable CUI markings.
Discussion
System media include digital and non-digital media. Marking refers to the use or application of human-readable security attributes. Labeling refers to the use of security attributes for internal system data structures. Digital media include diskettes, magnetic tapes, external or removable solid state or magnetic drives, flash drives, compact discs, and digital versatile discs. Non-digital media include paper and microfilm. CUI is defined by NARA along with marking, safeguarding, and dissemination requirements for such information.
Implementation perspective
Treat Media Marking as a CUI protection outcome that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to CUI media accountability, access, marking, storage, transport, sanitization, and disposal.
- Confirm the requirement is in scope for the CUI system components, services, users, and external connections being assessed.
- Resolve every organization-defined parameter through an approved governance and tailoring process.
- Map each clause of the requirement to an accountable owner, implementation mechanism, and evidence source.
- Verify that inherited and shared implementations are supported by current provider evidence and responsibility boundaries.
- Collect evidence during normal operation and review changes, exceptions, and deficiencies on a risk-based cadence.
Questions to ask
- Which CUI assets, data flows, users, and services are protected by this requirement?
- Which portions are implemented locally, inherited, shared, or not applicable, and what evidence supports that determination?
- Do the system security plan, deployed configuration, operating process, and assessment evidence tell the same story?
- What change, incident, or threshold should trigger reassessment?
Evidence and validation
- media inventories and chain-of-custody records
- sanitization certificates
- transport and storage procedures
- removable-media control logs
Common failure patterns
- cloud snapshots and virtual media excluded
- sanitization method not matched to media type
- untracked removable media
- disposal vendors accepted without verification
Assessment objectives and methods
Assessment objectives (3)
- SR-03.8.4.
system media that contain CUI are marked to indicate distribution limitations.
- SR-03.8.4.
system media that contain CUI are marked to indicate handling caveats.
- SR-03.8.4.
system media that contain CUI are marked to indicate applicable CUI markings.
Examine
- physical protection policy and procedures
- media protection policy and procedures
- procedures for media marking
- list of system media marking security attributes
- system security plan
- other relevant documents or records
Interview
- personnel with system media protection and marking responsibilities
- personnel with information security responsibilities
Test
- processes for marking information media
- mechanisms for supporting or implementing media marking
Source NIST SP 800-53 controls
These controls are referenced by the official SP 800-171 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.
Authoritative sources
- NIST SP 800-171 Revision 3 official publication ↗
- NIST SP 800-171A Revision 3 official publication ↗
- NIST OSCAL Content release used for this import ↗
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. The official publications, the responsible federal agency, and the governing contract or agreement determine applicability, tailoring, assessment depth, and required implementation.