Ensure SSH LogLevel is appropriate

MediumLevel 1Manual reviewcos

Description

INFO level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field. VERBOSE level specifies that login and logout activity as well as the key fingerprint for any SSH key used for login will be logged. This information is important for SSH key management, especially in legacy environments. SSH provides several logging levels with varying amounts of verbosity. DEBUG is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information.

How it is checked

Audit method: Manual review

This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.

Run the following command and verify that output matches: # sshd -T | grep loglevel LogLevel VERBOSE OR loglevel INFO

How it is fixed

Fix method: Guidance or infrastructure patch

Edit the /etc/ssh/sshd_config file to set the parameter as follows: LogLevel VERBOSE OR LogLevel INFO

Properties

Operating systems: Any
Tags: container-optimized-oscosloggingssh
Reference: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.5 Ensure SSH LogLevel is appropriate