# Cis GCP Cos 5.1.8

> Ensure SSH IgnoreRhosts is enabled

- Skill: `cyberstrikeus/cis-gcp-cos-5-1-8` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-gcp-cos-5-1-8`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-gcp-cos-5-1-8/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-gcp-cos-5-1-8

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# 5.1.8 Ensure SSH IgnoreRhosts is enabled (Automated)

## Description

The `IgnoreRhosts` parameter specifies that `.rhosts` and `.shosts` files will not be used in `RhostsRSAAuthentication` or `HostbasedAuthentication`.

## Rationale

Setting this parameter forces users to enter a password when authenticating with ssh.

## Audit Procedure

Run the following command and verify that output matches:

```bash
# sshd -T | grep ignorerhosts

IgnoreRhosts yes
```

## Expected Result

Output should show `IgnoreRhosts yes`.

## Remediation

Edit the `/etc/ssh/sshd_config` file to set the parameter as follows:

```
IgnoreRhosts yes
```

## Default Value

IgnoreRhosts yes

## CIS Controls

| Controls Version | Control                                                            | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------ | ---- | ---- | ---- |
| v8               | 4.4 Implement and Manage a Firewall on Servers                     | x    | x    | x    |
| v8               | 4.5 Implement and Manage a Firewall on End-User Devices            | x    | x    | x    |
| v7               | 9.2 Ensure Only Approved Ports, Protocols and Services Are Running |      | x    | x    |

## Profile

- Level 1 - Server