NIST SP 800-171 Rev. 3 3.13.4 — Information in Shared System Resources

What this control requires

This control prevents unauthorized and unintended information transfer via shared system resources. It ensures that information from prior users or roles is not accessible to current users or roles when shared system resources are released back to the system, including encrypted representations of information. This control supports the Information Transfer Protection capability within the Situational Awareness (3.13) family.

In plain English

This control prevents unauthorized and unintended information transfer via shared system resources. In practice, this means you can prove you access management-level controls on a defined cadence.

Why it matters

DoD contractors and their subcontractors must implement all 100 SP 800-171 requirements to keep CUI handling contracts. Gaps are scored against the SPRS scoring methodology; below a 110-point starting score, each unmet requirement deducts points and a below-threshold score can disqualify a bid.

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 C3PAO conducting a CMMC Level 2 assessment uses NIST SP 800-171A objectives. They expect a System Security Plan (SSP), Plan of Action & Milestones (POA&M) for any gaps, and objective evidence (configurations, ticket records, training records) for every requirement.

Within Situational Awareness, the assessor will trace your implementation back to the catalogue reference (Requirement 3.13.4) and look for objective evidence on the latest two assessment cycles.

How to implement

1. Write a short policy stating intent, scope and named owner.
2. Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy.
3. Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it.
4. Review on a documented cadence and capture the review in the risk register or compliance tracker.

Operational checklist

• Access. Document the trigger, the owner and the cadence.
• Information. Document the trigger, the owner and the cadence.
• Protection. Document the trigger, the owner and the cadence.
• System. Document the trigger, the owner and the cadence.
• Scope: management, protection.

Evidence to collect

• Identity Scan. IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: Information in Shared System Resources.

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.

• SOC 2 (2017 TSC) CC6.6 — Boundary Protection
• ISO/IEC 27001:2022 A.8.23 — Web filtering
• CIS Controls v8 9.2 — Use DNS Filtering Services
• ISO/IEC 27701:2025 A.3.8 — Identity management
• NIST SP 800-53 Rev. 5 MP-6(4) — Controlled Unclassified Information

Related controls in NIST SP 800-171 Rev. 3

• Requirement 3.13.14 — Technology-specific.
• Requirement 3.5.7 — Password Management
• Requirement 3.15.2 — System Security Plan
• Requirement 3.5.5 — Identifier Management
• Requirement 3.9.1 — Personnel Screening
• Requirement 3.8.5 — Media Transport

References

• NIST Computer Security Resource Center — NIST SP 800-171 Rev. 3
• Catalogue identifier: Requirement 3.13.4

Topics: identity accessidentity managementaccess reviewprivileged access