# Cis Ubuntu1804 V220 1 5 4

> Ensure prelink is not installed

- Skill: `cyberstrikeus/cis-ubuntu1804-v220-1-5-4` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1804-v220-1-5-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1804-v220-1-5-4/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/cis-ubuntu1804-v220-1-5-4

---


# 1.5.4 Ensure prelink is not installed (Automated)

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

`prelink` is a program that modifies ELF shared libraries and ELF dynamically linked binaries in such a way that the time needed for the dynamic linker to perform relocations at startup significantly decreases.

## Rationale

The prelinking feature can interfere with the operation of AIDE, because it changes binaries. Prelinking can also increase the vulnerability of the system if a malicious user is able to compromise a common library such as libc.

## Audit Procedure

### Command Line

Verify `prelink` is not installed:

```bash
dpkg-query -s prelink &>/dev/null && echo "prelink is installed"
```

## Expected Result

Nothing should be returned.

## Remediation

### Command Line

Run the following command to restore binaries to normal:

```bash
prelink -ua
```

Uninstall `prelink` using the appropriate package manager or manual installation:

```bash
apt purge prelink
```

## References

1. NIST SP 800-53 Rev. 5: CM-6, CM-1, CM-3

## CIS Controls

| Controls Version | Control                                                             | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------- | ---- | ---- | ---- |
| v8               | 3.14 Log Sensitive Data Access                                      |      |      | X    |
| v7               | 14.9 Enforce Detail Logging for Access or Changes to Sensitive Data |      |      | X    |

## MITRE ATT&CK Mappings

| Techniques / Sub-techniques        | Tactics | Mitigations |
| ---------------------------------- | ------- | ----------- |
| T1055, T1055.009, T1065, T1065.001 | TA0002  | M1050       |