SA 21(1) Validation Of Screening

---
name: "SA-21(1)_validation-of-screening"
description: "Validation of Screening"
category: "configuration"
version: "5.2.0"
author: "cyberstrike-official"
tags:
  - nist
  - sp800-53
  - rev5
  - sa-21-1
  - sa
  - enhancement
tech_stack:
  - any
cwe_ids:
  - CWE-16
chains_with: []
prerequisites:
  - SA-21
severity_boost: {}
---

# SA-21(1) Validation of Screening

> **Enhancement of:** SA-21

## High-Level Description

**Family:** System and Services Acquisition (SA)
**Framework:** NIST SP 800-53 Rev 5

No description available.

## What to Check

- [ ] Verify SA-21(1) Validation of Screening is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for SA-21(1)
- [ ] Verify enhancement builds upon base control SA-21

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SA-21(1) 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 |
| ------------- | --------------------------------- | ----- |
| Manual Review | Documentation and interview-based | N/A   |

## Remediation Guide

### Control Statement

Refer to NIST SP 800-53 Rev 5 for the full control statement.

### Implementation Guidance

Implement this control per organizational risk assessment and system categorization.

## Risk Assessment

| Finding                                          | Severity | Impact                                     |
| ------------------------------------------------ | -------- | ------------------------------------------ |
| SA-21(1) Validation of Screening not implemented | Medium   | System and Services Acquisition            |
| SA-21(1) partially implemented                   | Low      | Incomplete System and Services Acquisition |

## CWE Categories

| CWE ID | Title         |
| ------ | ------------- |
| CWE-16 | Configuration |

## References

- [NIST SP 800-53 Rev 5 - SA-21(1)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=sa-21.1)
- [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