cis-gcp-cos-5-1-7

name	cis-gcp-cos-5.1.7
description	Ensure SSH MaxAuthTries is set to 4 or less
category	cis-gcp-cos
version	1.2.0
author	cyberstrike-official
tags	["cis","gcp","container-optimized-os","ssh","sshd","sshd-config","authentication"]
cis_id	5.1.7
cis_benchmark	CIS Google Container-Optimized OS Benchmark v1.2.0
tech_stack	["gcp","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

5.1.7 Ensure SSH MaxAuthTries is set to 4 or less (Automated)

Description

The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. When the login failure count reaches half the number, error messages will be written to the journald logs detailing the login failure.

Rationale

Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server. While the recommended setting is 4, set the number based on site policy.

Audit Procedure

Run the following command and verify that output MaxAuthTries is 4 or less:

# sshd -T | grep maxauthtries

MaxAuthTries 4

Expected Result

Output should show MaxAuthTries set to 4 or less.

Remediation

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

MaxAuthTries 4

Default Value

MaxAuthTries 6

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	8.2 Collect Audit Logs	x	x	x
v7	16.13 Alert on Account Login Behavior Deviation			x

Profile

• Level 2 - Server