NIST SP 800-171 Rev. 3 3.7.5 — Nonlocal Maintenance

What this control requires

This control requires the approval and monitoring of nonlocal Maintenance and diagnostic activities. It mandates the use of multi-factor authentication and replay resistance for establishing nonlocal sessions, and the termination of sessions and network connections once Maintenance is completed. This control supports the Nonlocal Maintenance Management capability within the Maintenance (3.7) family.

In plain English

This control requires the approval and monitoring of nonlocal Maintenance and diagnostic activities. 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 Maintenance, the assessor will trace your implementation back to the catalogue reference (Requirement 3.7.5) 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.
• Multi-Factor. Document the trigger, the owner and the cadence.
• Authentication. Document the trigger, the owner and the cadence.
• Maintenance. Document the trigger, the owner and the cadence.
• Nonlocal. Document the trigger, the owner and the cadence.
• Scope: management, termination, authentication, maintenance.

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: Nonlocal Maintenance.

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.

• NIST SP 800-53 Rev. 5 MA-3(5) — Execution With Privilege
• ISO/IEC 27001:2022 A.8.23 — Web filtering
• SOC 2 (2017 TSC) CC1.5 — Accountability for Internal Control Responsibilities
• CIS Controls v8 9.2 — Use DNS Filtering Services
• BSI C5:2020 AM-05 — Commitment to Permissible Use, Safe Handling and Return of Assets

Related controls in NIST SP 800-171 Rev. 3

• Requirement 3.5.5 — Identifier Management
• Requirement 3.13.4 — Information in Shared System Resources
• Requirement 3.5.7 — Password Management
• Requirement 3.9.2 — Personnel Termination and Transfer
• Requirement 3.9.1 — Personnel Screening
• Requirement 3.1.11 — Session Termination

References

• NIST Computer Security Resource Center — NIST SP 800-171 Rev. 3
• Catalogue identifier: Requirement 3.7.5

Topics: identity accessidentity managementaccess reviewprivileged accesscontinuous monitoring