SLEM 5 must log SSH connection attempts and failures to the server.

Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk and make remote user access management difficult at best.

Remote access is access to DoW nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless.

Automated monitoring of remote access sessions allows organizations to detect cyberattacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets).

Verify SSH is configured to verbosely log connection attempts and failed logon attempts to SLEM 5 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'
     /etc/ssh/sshd_config:LogLevel VERBOSE

If "LogLevel" is not set to "VERBOSE", is commented out, missing, or conflicting results are returned, this is a finding.

Configure SSH to verbosely log connection attempts and failed logon attempts to SLEM 5.

Add or modify the following line in the "/etc/ssh/sshd_config" file:

LogLevel VERBOSE

Restart the SSH daemon in order for the changes to take effect:

     > sudo systemctl restart sshd.service