NIST SP 800-171 Rev. 3·Requirement 3.15.2·high·Component: System and Information Integrity

What this control requires

This control requires developing a system security plan that outlines the system components, information types, threats, operational environment, security requirements, safeguards, and system roles and responsibilities. It also mandates reviewing and updating the plan regularly and ensuring its protection from unauthorized disclosure to safeguard Controlled Unclassified Information (CUI). This control supports the System Security Plan capability within the System and Information Integrity (3.15) family.
— NIST SP 800-171 Rev. 3, Requirement 3.15.2

In plain English

This control requires developing a system security plan that outlines the system components, information types, threats, operational environment, security requirements, safeguards, and system roles and responsibilities. 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 System and Information Integrity, the assessor will trace your implementation back to the catalogue reference (Requirement 3.15.2) 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.
  • Security. Document the trigger, the owner and the cadence.
  • Scope: management, cui, security, protection, security plan, system components.

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.
  • Infra Scan. Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: System Security Plan.

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.

Related controls in NIST SP 800-171 Rev. 3

References

Topics: identity accessidentity managementaccess reviewprivileged access