cis-gcp-cos-5-1-18

name	cis-gcp-cos-5.1.18
description	Ensure SSH warning banner is configured
category	cis-gcp-cos
version	1.2.0
author	cyberstrike-official
tags	["cis","gcp","container-optimized-os","ssh","sshd","sshd-config"]
cis_id	5.1.18
cis_benchmark	CIS Google Container-Optimized OS Benchmark v1.2.0
tech_stack	["gcp","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

5.1.18 Ensure SSH warning banner is configured (Automated)

Description

The Banner parameter specifies a file whose contents must be sent to the remote user before authentication is permitted. By default, no banner is displayed.

Rationale

Banners are used to warn connecting users of the particular site's policy regarding connection. Presenting a warning message prior to the normal user login may assist the prosecution of trespassers on the computer system.

Audit Procedure

Run the following command and verify that output matches:

# sshd -T | grep banner

Banner /etc/issue.net

Expected Result

Output should show Banner /etc/issue.net.

Remediation

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

Banner /etc/issue.net

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v7	5.1 Establish Secure Configurations	x	x	x

Profile

• Level 2 - Server