# SI-2(6)_removal-of-previous-versions-of-software-and-firmware

> Remove previous versions of [organization-defined] after updated versions have been installed.

- Skill: `cyberstrikeus/si-2-6-removal-of-previous-versions-of-software-and-firmware` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/si-2-6-removal-of-previous-versions-of-software-and-firmware`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/si-2-6-removal-of-previous-versions-of-software-and-firmware/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- 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/si-2-6-removal-of-previous-versions-of-software-and-firmware

---


# SI-2(6) Removal of Previous Versions of Software and Firmware

> **Enhancement of:** SI-2

## High-Level Description

**Family:** System and Information Integrity (SI)
**Framework:** NIST SP 800-53 Rev 5

Previous versions of software or firmware components that are not removed from the system after updates have been installed may be exploited by adversaries. Some products may automatically remove previous versions of software and firmware from the system.

## What to Check

- [ ] Verify SI-2(6) Removal of Previous Versions of Software and Firmware is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for SI-2(6)
- [ ] Verify enhancement builds upon base control SI-2

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SI-2(6) 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 integrity monitoring | `cloud_audit_monitoring`       |
| AWS CLI         | Review GuardDuty/Inspector | `aws guardduty list-detectors` |

## Remediation Guide

### Control Statement

Remove previous versions of [organization-defined] after updated versions have been installed.

### Implementation Guidance

Previous versions of software or firmware components that are not removed from the system after updates have been installed may be exploited by adversaries. Some products may automatically remove previous versions of software and firmware from the system.

## Risk Assessment

| Finding                                                                       | Severity | Impact                                      |
| ----------------------------------------------------------------------------- | -------- | ------------------------------------------- |
| SI-2(6) Removal of Previous Versions of Software and Firmware not implemented | High     | System and Information Integrity            |
| SI-2(6) partially implemented                                                 | Medium   | Incomplete System and Information Integrity |

## CWE Categories

| CWE ID | Title                     |
| ------ | ------------------------- |
| CWE-20 | Improper Input Validation |

## References

- [NIST SP 800-53 Rev 5 - SI-2(6)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=si-2.6)
- [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