NIST SP 800-171 Rev. 3 3.1.4 — Separation of Duties : iCompaas Support

NIST SP 800-171 Rev. 3·Requirement 3.1.4·high·Component: Access Control

What this control requires

This control ensures that duties requiring separation to prevent abuse of authorized privileges are identified and defined. It establishes system access authorizations to support the division of tasks, such as separating mission and support functions, and ensuring that personnel responsible for access control do not also handle audit functions. This reduces the risk of unauthorized activity or collusion within the organization. This control supports the Separation of Duties Enforcement capability within the Access Control (3.1) family.
— NIST SP 800-171 Rev. 3, Requirement 3.1.4

In plain English

This control ensures that duties requiring separation to prevent abuse of authorized privileges are identified and defined. 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 Access Control, the assessor will trace your implementation back to the catalogue reference (Requirement 3.1.4) and look for objective evidence on the latest two assessment cycles.

How to implement

Logging Monitoring

AWS. Org-trail CloudTrail to a central log archive account, GuardDuty in every region, and Security Hub for cross-source correlation.

Azure. Pipe every diagnostic setting into a central Log Analytics workspace; onboard Microsoft Sentinel for SIEM/SOAR.

GCP. Aggregate audit logs in a dedicated logging project with sink to BigQuery; enable Security Command Center Premium and route findings to Chronicle SIEM.

Operational checklist

Access. Document the trigger, the owner and the cadence.
Separation. Document the trigger, the owner and the cadence.
Access Control. Document the trigger, the owner and the cadence.
Authorized. Document the trigger, the owner and the cadence.
System. Document the trigger, the owner and the cadence.
Scope: management, enforcement, support functions, personnel, access authorizations, access control.

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: Separation of Duties.

Common pitfalls

Per-account logging that nobody stitches together at the org level — incidents that cross accounts go undetected for days.

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

NIST Computer Security Resource Center — NIST SP 800-171 Rev. 3
Catalogue identifier: Requirement 3.1.4

Topics: governance riskidentity accessidentity managementaccess reviewprivileged accesslogging monitoring

NIST SP 800-171 Rev. 3 3.1.4 — Separation of Duties