# PL-8(1)_defense-in-depth

> Design the security and privacy architectures for the system using a defense-in-depth approach that: Allocates [organization-defined] to [organization

- Skill: `cyberstrikeus/pl-8-1-defense-in-depth` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/pl-8-1-defense-in-depth`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/pl-8-1-defense-in-depth/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/pl-8-1-defense-in-depth

---


# PL-8(1) Defense in Depth

> **Enhancement of:** PL-8

## High-Level Description

**Family:** Planning (PL)
**Framework:** NIST SP 800-53 Rev 5

Organizations strategically allocate security and privacy controls in the security and privacy architectures so that adversaries must overcome multiple controls to achieve their objective. Requiring adversaries to defeat multiple controls makes it more difficult to attack information resources by increasing the work factor of the adversary; it also increases the likelihood of detection. The coordination of allocated controls is essential to ensure that an attack that involves one control does not create adverse, unintended consequences by interfering with other controls. Unintended consequences can include system lockout and cascading alarms. The placement of controls in systems and organizations is an important activity that requires thoughtful analysis. The value of organizational assets is an important consideration in providing additional layering. Defense-in-depth architectural approaches include modularity and layering (see [SA-8(3)](#sa-8.3) ), separation of system and user functionality (see [SC-2](#sc-2) ), and security function isolation (see [SC-3](#sc-3)).

## What to Check

- [ ] Verify PL-8(1) Defense in Depth is documented in SSP
- [ ] Validate all 2 control requirements are implemented
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for PL-8(1)
- [ ] Verify enhancement builds upon base control PL-8

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for PL-8(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

Design the security and privacy architectures for the system using a defense-in-depth approach that:
Allocates [organization-defined] to [organization-defined] ; and
Ensures that the allocated controls operate in a coordinated and mutually reinforcing manner.

### Implementation Guidance

Organizations strategically allocate security and privacy controls in the security and privacy architectures so that adversaries must overcome multiple controls to achieve their objective. Requiring adversaries to defeat multiple controls makes it more difficult to attack information resources by increasing the work factor of the adversary; it also increases the likelihood of detection. The coordination of allocated controls is essential to ensure that an attack that involves one control does not create adverse, unintended consequences by interfering with other controls. Unintended consequences can include system lockout and cascading alarms. The placement of controls in systems and organizations is an important activity that requires thoughtful analysis. The value of organizational assets is an important consideration in providing additional layering. Defense-in-depth architectural approaches include modularity and layering (see [SA-8(3)](#sa-8.3) ), separation of system and user functionality (see [SC-2](#sc-2) ), and security function isolation (see [SC-3](#sc-3)).

## Risk Assessment

| Finding                                  | Severity | Impact              |
| ---------------------------------------- | -------- | ------------------- |
| PL-8(1) Defense in Depth not implemented | Medium   | Planning            |
| PL-8(1) partially implemented            | Low      | Incomplete Planning |

## CWE Categories

| CWE ID | Title                 |
| ------ | --------------------- |
| N/A    | No direct CWE mapping |

## References

- [NIST SP 800-53 Rev 5 - PL-8(1)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=pl-8.1)
- [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 (SC-2, SC-3, SC-29, SC-36) reviewed