# NIST SP 800-53 Rev. 5 SC-37 — Out-Of-Band Channels - Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-37-out-of-band-channels - 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) › SC — System and Communications Protection - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **NIST SP 800-53 Rev. 5**·Control `SC-37`·high·Component: **System and Communications Protection** ## What this control requires > Use out-of-band channels for the physical delivery or electronic transmission of organization-defined information, system components, or devices to specified individuals or systems. These channels, such as non-network accesses or separate network paths, ensure confidentiality, integrity, and availability, as they are less vulnerable than in-band channels that carry operational traffic. This control supports the Out-of-Band Communication System capability within the System and Communications Protection family. > > — NIST SP 800-53 Rev. 5, Control SC-37 ### In plain English Use out-of-band channels for the physical delivery or electronic transmission of organization-defined information, system components, or devices to specified individuals or systems. In practice, this means you can prove you information information-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-37) 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. #### Network Security **AWS.** VPC Flow Logs to S3, default-deny security groups, AWS Network Firewall for north-south, and Transit Gateway for hub-and-spoke segmentation. **Azure.** NSGs with deny-by-default, Azure Firewall Premium with TLS inspection, Private Endpoints for PaaS, and Microsoft Defender for Cloud's secure score for drift. **GCP.** VPC Service Controls perimeters around sensitive APIs, Cloud NGFW Enterprise for L7 inspection, Private Service Connect for managed services. #### 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 - **Information.** 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. - **Network.** Document the trigger, the owner and the cadence. - **Separate.** Document the trigger, the owner and the cadence. - **Scope:** information, organization, system, protection, components, capability, systems, transmission. ## 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: Out-Of-Band Channels. ## Common pitfalls - Pilot MDM rollouts that quietly exclude executives or engineers; carving out the highest-risk users is the most common audit failure. - Default-allow egress rules; East-West traffic with no segmentation; jump hosts on the public internet with password auth. ## Related controls in NIST SP 800-53 Rev. 5 - [**Control SC-37(1)** — Ensure Delivery And Transmission](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-37-1-ensure-delivery-and-transmission) - [**Control SC-8** — Transmission Confidentiality And Integrity](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-8-transmission-confidentiality-and-integrity) - [**Control SC-5(1)** — Restrict Ability To Attack Other Systems](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-5-1-restrict-ability-to-attack-other-systems) - [**Control SC-15(3)** — Disabling And Removal In Secure Work Areas](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-15-3-disabling-and-removal-in-secure-work-areas) - [**Control SC-7(7)** — Split Tunneling For Remote Devices](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-7-7-split-tunneling-for-remote-devices) - [**Control SC-15(1)** — Physical Or Logical Disconnect](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-15-1-physical-or-logical-disconnect) ## 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 SC-37` Topics: endpoint securityendpoint protectionnetwork securityphysical security ## 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.