NIST SP 800-53 Rev. 5 PE-3(4) — Lockable Casings

What this control requires

Use lockable casings to protect defined system components (e.g., portable devices) from unauthorized physical access, reducing theft risks. This control supports the Physical Security System capability within the Physical and Environmental Protection family.

In plain English

Use lockable casings to protect defined system components (e.g., portable devices) from unauthorized physical access, reducing theft risks. In practice, this means you can prove you access system-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.

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 Physical and Environmental Protection, the assessor will trace your implementation back to the catalogue reference (Control PE-3(4)) and look for objective evidence on the latest two assessment cycles.

How to implement

Endpoint Protection

MDM. Make MDM enrollment a hard gate for device access (Intune compliance + Conditional Access, or Jamf + Okta device trust). Unmanaged devices simply don't get a session token.

EDR. Deploy CrowdStrike / SentinelOne / Defender for Endpoint to every server and laptop; alert on any host that stops sending telemetry for >24h.

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.
• Physical. Document the trigger, the owner and the cadence.
• Protection. Document the trigger, the owner and the cadence.
• Portable. Document the trigger, the owner and the cadence.
• Scope: system, e, protection, components, capability, casings, physical access, system components.

Evidence to collect

• User Device Scan. MDM compliance state per user device (Intune / Jamf / Workspace ONE).

Endpoint compliance telemetry (Intune, Jamf) proves managed coverage. Focus: Lockable Casings.

Common pitfalls

• Pilot MDM rollouts that quietly exclude executives or engineers; carving out the highest-risk users is the most common audit failure.

Related controls in NIST SP 800-53 Rev. 5

• Control AT-3(2) — Physical Security Controls
• Control PE-3(5) — Tamper Protection
• Control PE-10 — Emergency Shutoff
• Control PE-3 — Physical Access Control
• Control PE-3(1) — System Access
• Control PE-5(3) — Marking Output Devices

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control PE-3(4)

Topics: endpoint securityendpoint protectionphysical security