SC 43 Usage Restrictions

---
name: "SC-43_usage-restrictions"
description: "Establish usage restrictions and implementation guidelines for the following system components: [organization-defined] ;"
category: "configuration"
version: "5.2.0"
author: "cyberstrike-official"
tags:
  - nist
  - sp800-53
  - rev5
  - sc-43
  - sc
tech_stack:
  - aws
  - azure
  - gcp
  - linux
  - windows
  - network
cwe_ids:
  - CWE-311
chains_with:
  - AC-18
  - AC-19
  - CM-6
  - SC-7
  - SC-18
prerequisites: []
severity_boost:
  AC-18: "Chain with AC-18 for comprehensive security coverage"
  AC-19: "Chain with AC-19 for comprehensive security coverage"
  CM-6: "Chain with CM-6 for comprehensive security coverage"
---

# SC-43 Usage Restrictions

## High-Level Description

**Family:** System and Communications Protection (SC)
**Framework:** NIST SP 800-53 Rev 5

Usage restrictions apply to all system components including but not limited to mobile code, mobile devices, wireless access, and wired and wireless peripheral components (e.g., copiers, printers, scanners, optical devices, and other similar technologies). The usage restrictions and implementation guidelines are based on the potential for system components to cause damage to the system and help to ensure that only authorized system use occurs.

## What to Check

- [ ] Verify SC-43 Usage Restrictions is documented in SSP
- [ ] Validate all 2 control requirements are implemented
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for SC-43

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-43 implementation details. Verify the organization has documented how this control is satisfied.

### Step 2: Validate Implementation

```
# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null
```

### Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

## Tools

| Tool            | Purpose                               | Usage                                |
| --------------- | ------------------------------------- | ------------------------------------ |
| cloud-audit-mcp | Check encryption and network controls | `cloud_audit_encryption`             |
| nmap            | Network scanning                      | `nmap -sV --script ssl-enum-ciphers` |

## Remediation Guide

### Control Statement

Establish usage restrictions and implementation guidelines for the following system components: [organization-defined] ; and
Authorize, monitor, and control the use of such components within the system.

### Implementation Guidance

Usage restrictions apply to all system components including but not limited to mobile code, mobile devices, wireless access, and wired and wireless peripheral components (e.g., copiers, printers, scanners, optical devices, and other similar technologies). The usage restrictions and implementation guidelines are based on the potential for system components to cause damage to the system and help to ensure that only authorized system use occurs.

## Risk Assessment

| Finding                                  | Severity | Impact                                          |
| ---------------------------------------- | -------- | ----------------------------------------------- |
| SC-43 Usage Restrictions not implemented | High     | System and Communications Protection            |
| SC-43 partially implemented              | Medium   | Incomplete System and Communications Protection |

## CWE Categories

| CWE ID  | Title                                |
| ------- | ------------------------------------ |
| CWE-311 | Missing Encryption of Sensitive Data |

## References

- [NIST SP 800-53 Rev 5 - SC-43](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=sc-43)
- [NIST SP 800-53A Rev 5 (Assessment Procedures)](https://csrc.nist.gov/pubs/sp/800/53/a/r5/final)
- [NIST SP 800-53 Rev 5 Full Catalog](https://csrc.nist.gov/pubs/sp/800/53/r5/upd1/final)

## Checklist

- [ ] Control documented in SSP
- [ ] Implementation evidence collected
- [ ] Operating effectiveness validated
- [ ] Continuous monitoring in place
- [ ] Related controls (AC-18, AC-19, CM-6, SC-7, SC-18) reviewed