DISA STIGS Viewer

OL 9 must log SSH connection attempts and failures to the server.

Overview

Finding ID Version Rule ID IA Controls Severity
V-271703 OL09-00-002340 SV-271703r1091821_rule   Medium
Description
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. "INFO" or "VERBOSE" 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.
STIG Date
Oracle Linux 9 Security Technical Implementation Guide 2025-05-08

Details

Check Text (C-75753r1091819_chk)
Verify that OL 9 logs SSH connection attempts and failures to the server.

Check what the SSH daemon's "LogLevel" option is set to with the following command:

$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*loglevel'
LogLevel VERBOSE

If a value of "VERBOSE" is not returned, the line is commented out, or is missing, this is a finding.
Fix Text (F-75660r1091820_fix)
Configure OL 9 to log connection attempts add or modify the following line in "/etc/ssh/sshd_config" or in a file in "/etc/ssh/sshd_config.d".

LogLevel VERBOSE

Restart the SSH daemon for the settings to take effect:

$ sudo systemctl restart sshd.service