NIST SP 800-171 Rev. 3·Requirement 3.4.2·high·Component: Configuration Management

What this control requires

This control requires the establishment, documentation, and implementation of configuration settings that reflect the most restrictive mode consistent with operational requirements. It also mandates the identification, documentation, and approval of any deviations from established configuration settings. These settings encompass security parameters such as account, file, directory permissions, and configurations for network components, operating systems, and applications. This control supports the Configuration Management System capability within the Configuration Management (3.4) family.
— NIST SP 800-171 Rev. 3, Requirement 3.4.2

In plain English

This control requires the establishment, documentation, and implementation of configuration settings that reflect the most restrictive mode consistent with operational requirements. In practice, this means you can prove you account 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 Configuration Management, the assessor will trace your implementation back to the catalogue reference (Requirement 3.4.2) and look for objective evidence on the latest two assessment cycles.

How to implement

Configuration Management

Policy-as-code. Codify the control as Service Control Policies (AWS), Azure Policy initiatives, or Organisation Policy (GCP) so the platform enforces what the document promises.

IaC. Gate Terraform / Pulumi / CloudFormation changes with Checkov / tfsec / OPA so misconfigurations never reach production.

Drift. Run a CSPM (Wiz / Prisma / Defender for Cloud / Security Command Center) over every account and route findings to a single risk register.

Operational checklist

  • Account. Document the trigger, the owner and the cadence.
  • Access. Document the trigger, the owner and the cadence.
  • Configuration. Document the trigger, the owner and the cadence.
  • System. Document the trigger, the owner and the cadence.
  • Risk. Document the trigger, the owner and the cadence.
  • Scope: management, configuration, settings, account, file, directory permissions, applications, security.

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: Configuration Settings.

Common pitfalls

  • Manual cloud-console changes that never make it back to Terraform — drift accumulates until the next outage forces a reconciliation.

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: governance riskidentity accessidentity managementaccess reviewprivileged accessconfiguration management