# NIST SP 800-53 Rev. 5 AC-4(31) — Failed Content Transfer Prevention - Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-31-failed-content-transfer-prevention - Section: [Compliance](https://support.icompaas.com/compliance) › [NIST SP 800-53 Rev. 5 Controls](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5) › AC — Access Control - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **NIST SP 800-53 Rev. 5**·Control `AC-4(31)`·critical·Component: **Access Control** ## What this control requires > When transferring information between different security domains, organizations must prevent the transfer of failed content to the receiving domain. Content that fails filtering checks can compromise the system if transferred, potentially causing corruption or security issues in the receiving domain. This control supports the Governance capability within the Access Control family. > > — NIST SP 800-53 Rev. 5, Control AC-4(31) ### In plain English When transferring information between different security domains, organizations must prevent the transfer of failed content to the receiving domain. 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 **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 **Access Control**, the assessor will trace your implementation back to the catalogue reference (Control AC-4(31)) and look for objective evidence on the latest two assessment cycles. ## How to implement #### 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. - **Access.** Document the trigger, the owner and the cadence. - **Information.** 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. - **Scope:** management, access control, information, domains, system, content transfer prevention, checks, capability. ## Evidence to collect - **Policy Document.** A signed and version-controlled policy / standard / procedure document. Signed policy or standard documents the safeguard. Focus: Failed Content Transfer Prevention. ## Common pitfalls - 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. - [**NIST SP 800-171 Rev. 3 3.1.5** — Least Privilege](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-1-5-least-privilege) - [**HIPAA (45 CFR Part 164) 164.308(a)(1)(ii)(D)** — Security Management Process -Information System Activity Review](https://support.icompaas.com/compliance/hipaa/164-308-a-1-ii-d-security-management-process-information-system-activity-review) - [**ISO/IEC 27001:2022 A.5.1** — Policies for information security](https://support.icompaas.com/compliance/iso-27001-2022/a-5-1-policies-for-information-security) - [**BSI C5:2020 SP-01** — Documentation, communication and provision of policies and instructions](https://support.icompaas.com/compliance/bsi-c5-2020/sp-01-documentation-communication-and-provision-of-policies-and-instructions) ## Related controls in NIST SP 800-53 Rev. 5 - [**Control AC-4(24)** — Internal Normalized Format](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-24-internal-normalized-format) - [**Control AC-4(26)** — Audit Filtering Actions](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-26-audit-filtering-actions) - [**Control AC-4(27)** — Redundant/Independent Filtering Mechanisms](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-27-redundant-independent-filtering-mechanisms) - [**Control AC-4(20)** — Approved Solutions](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-20-approved-solutions) - [**Control AC-4(30)** — Filter Mechanisms Using Multiple Processes](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-30-filter-mechanisms-using-multiple-processes) - [**Control AC-4(25)** — Data Sanitization](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ac-4-25-data-sanitization) ## References - [NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5](https://csrc.nist.gov/Projects/risk-management/sp800-53-controls) - Catalogue identifier: `Control AC-4(31)` Topics: governance riskpolicy management ## Related compliance guidance - [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): Start with the full NIST SP 800-53 implementation guide — scope, roadmap, evidence and how the assessment runs. - [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): If your obligation is protecting CUI in your own systems for a federal or defence contract, this derived subset — not the full catalogue — is the requirement. - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most commercial SaaS already hold a SOC 2 Type 2, and FedRAMP 20x Class A is designed for providers that have one.