NIST SP 800-53 Rev. 5 SC-18(1) — Identify Unacceptable Code And Take Corrective Actions : iCompaas Support

NIST SP 800-53 Rev. 5·Control SC-18(1)·high·Component: System and Communications Protection

What this control requires

Identify organization-defined unacceptable mobile code and take organization-defined corrective actions when detected. Corrective actions may include blocking, quarantining, or alerting administrators. For example, blocking the transmission of word processing files with embedded macros that have been classified as unacceptable mobile code. This control supports the Mobile Code Detection and Management System capability within the System and Communications Protection family.
— NIST SP 800-53 Rev. 5, Control SC-18(1)

In plain English

Identify organization-defined unacceptable mobile code and take organization-defined corrective actions when detected. In practice, this means you can prove you policy 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 high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

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-18(1)) 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

Policy. Document the trigger, the owner and the cadence.
Detection. Document the trigger, the owner and the cadence.
Protection. Document the trigger, the owner and the cadence.
System. Document the trigger, the owner and the cadence.
Control. Document the trigger, the owner and the cadence.
Scope: management, actions, organization, system, protection, capability, transmission, policy.

Evidence to collect

Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Identify Unacceptable Code And Take Corrective Actions.

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 800-53 Rev. 5

References

NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
Catalogue identifier: Control SC-18(1)

Topics: governance riskendpoint protectionpolicy management

NIST SP 800-53 Rev. 5 SC-18(1) — Identify Unacceptable Code And Take Corrective Actions