# SC-7(19)_block-communication-from-non-organizationally-configured-hos

> Block inbound and outbound communications traffic between [organization-defined] that are independently configured by end users and external service p

- Skill: `cyberstrikeus/sc-7-19-block-communication-from-non-organizationally-config` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/sc-7-19-block-communication-from-non-organizationally-config`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/sc-7-19-block-communication-from-non-organizationally-config/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector CAUTION)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/sc-7-19-block-communication-from-non-organizationally-config

---


# SC-7(19) Block Communication from Non-organizationally Configured Hosts

> **Enhancement of:** SC-7

## High-Level Description

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

Communication clients independently configured by end users and external service providers include instant messaging clients and video conferencing software and applications. Traffic blocking does not apply to communication clients that are configured by organizations to perform authorized functions.

## What to Check

- [ ] Verify SC-7(19) Block Communication from Non-organizationally Configured Hosts is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for SC-7(19)
- [ ] Verify enhancement builds upon base control SC-7

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-7(19) 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

Block inbound and outbound communications traffic between [organization-defined] that are independently configured by end users and external service providers.

### Implementation Guidance

Communication clients independently configured by end users and external service providers include instant messaging clients and video conferencing software and applications. Traffic blocking does not apply to communication clients that are configured by organizations to perform authorized functions.

## Risk Assessment

| Finding                                                                                 | Severity | Impact                                          |
| --------------------------------------------------------------------------------------- | -------- | ----------------------------------------------- |
| SC-7(19) Block Communication from Non-organizationally Configured Hosts not implemented | High     | System and Communications Protection            |
| SC-7(19) 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-7(19)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=sc-7.19)
- [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 (none) reviewed