NIST SP 800-171 Rev. 3 3.1.10 — Device Lock : iCompaas Support

NIST SP 800-171 Rev. 3·Requirement 3.1.10·medium·Component: Access Control

What this control requires

This control ensures that access to the system is prevented by initiating a device lock after a specified period of inactivity or requiring the user to lock the device before leaving it unattended. The lock conceals any previously visible information and retains access until the user reestablishes authentication through established identification procedures. This control supports the Device Lock Mechanism capability within the Access Control (3.1) family.
— NIST SP 800-171 Rev. 3, Requirement 3.1.10

In plain English

This control ensures that access to the system is prevented by initiating a device lock after a specified period of inactivity or requiring the user to lock the device before leaving it unattended. 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.

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 3.1.10) 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.

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

Access. Document the trigger, the owner and the cadence.
Information. Document the trigger, the owner and the cadence.
Device. Document the trigger, the owner and the cadence.
Access Control. Document the trigger, the owner and the cadence.
Protection. Document the trigger, the owner and the cadence.
Scope: management, lock, inactivity, authentication, access control, protection, procedures.

Evidence to collect

Policy Document. A signed and version-controlled policy / standard / procedure document.
Infra Scan. Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings.

Signed policy or standard documents the safeguard. Focus: Device Lock.

Common pitfalls

Pilot MDM rollouts that quietly exclude executives or engineers; carving out the highest-risk users is the most common audit failure.
Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

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 3.1.10

Topics: governance riskendpoint protectionidentity managementpolicy management

NIST SP 800-171 Rev. 3 3.1.10 — Device Lock