NIST SP 800-53 Rev. 5 SC-32(1) — Separate Physical Domains For Privileged Functions

What this control requires

Partition privileged functions into separate physical domains to prevent a single point of failure. If these functions operate within a single physical domain, a compromise or denial of service in that domain could affect the integrity of the privileged functions. Separating them into distinct physical domains enhances security by isolating risks. This control supports the Privileged Function Partitioning System capability within the System and Communications Protection family.

In plain English

Partition privileged functions into separate physical domains to prevent a single point of failure. In practice, this means you can prove you access management-level controls on a defined cadence.

Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

This control is rated critical in the source catalogue. Treat gaps here as production incidents in the risk register, not housekeeping.

What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within System and Communications Protection, the assessor will trace your implementation back to the catalogue reference (Control SC-32(1)) and look for objective evidence on the latest two assessment cycles.

How to implement

Physical Security

Inheritance. For cloud-only operations, inherit physical controls from the provider's SOC 2 / ISO 27001 report and document the inheritance in the SoA.

Operational checklist

• Access. Document the trigger, the owner and the cadence.
• Security. Document the trigger, the owner and the cadence.
• Domain. Document the trigger, the owner and the cadence.
• Physical. Document the trigger, the owner and the cadence.
• Separate. Document the trigger, the owner and the cadence.
• Scope: management, domains, system, service, functions, failure, protection, identity.

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: Separate Physical Domains For Privileged Functions.

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 800-171 Rev. 3 3.15.2 — System Security Plan
• SOC 2 (2017 TSC) CC6.2 — Access Provisioning
• CIS Controls v8 5.6 — Centralize Account Management
• ISO/IEC 27001:2022 A.5.15 — Access control

Related controls in NIST SP 800-53 Rev. 5

• Control SC-2(1) — Interfaces For Non-Privileged Users
• Control SC-2 — Separation Of System And User Functionality
• Control SC-20 — Secure Name/Address Resolution Service (Authoritative Source)
• Control SC-11 — Trusted Path
• Control SC-3 — Security Function Isolation
• Control SC-20(2) — Data Origin And Integrity

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control SC-32(1)

Topics: privileged accessidentity managementaccess reviewphysical security