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

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-261338	SRG-OS-000032-GPOS-00013	SLEM-05-255065	SV-261338r996845_rule	2024-06-04	1

Description
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 DOD 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).

Description

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 DOD 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).

ℹ️ Check
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.

ℹ️ Check

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.

✔️ Fix
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