V-280986

Discussion

Unintentionally running a rsyslog server accepting remote messages puts the system at increased risk. Malicious rsyslog messages sent to the server could exploit vulnerabilities in the server software, introduce misleading information into the system's logs, or fill the system's storage, leading to a denial of service. If the system is intended to be a log aggregation server, its use must be documented with the information system security officer.

Check Content

Note: If the SA can demonstrate that another tool (e.g., SPLUNK) is being used to manage log off-load and aggregation in lieu of rsyslog, this check is not applicable.

Verify RHEL 10 is not configured to receive remote logs using rsyslog.

Verify the setting with the following commands:

$ ss -tulnp | grep rsyslog

If no output is returned, rsyslog is not listening for remote logs.

If output appears, check for configured ports (514 is the default for syslog).

Check for remote logging configuration in rsyslog by examining the rsyslog configuration files:

$ sudo grep -E 'InputTCPServerRun|UDPServerRun|RELPServerRun|imtcp|imudp|imrelp' /etc/rsyslog.conf /etc/rsyslog.d/*

If this command returns uncommented lines enabling network listeners, the system is accepting remote logs. If this system is not documented and authorized as a log aggregation server, this is a finding.

Note: An error about no files or directories from the above commands may be returned. This is not a finding. Additionally, if a port option used together with a target and protocol is returned from inside an action block, this is not a finding.