cyberstrikeus 5.1.2.7 Ensure rsyslog is not configured to receive logs from a remote client (Automated)
Profile
- Level: 1 - Server
- Level: 1 - Workstation
- Assessment Status: Automated
Description
RSyslog supports the ability to receive messages from remote hosts, thus acting as a log server. Clients should not receive data from other hosts.
Rationale
If a client is configured to also receive data, thus turning it into a server, the client system is acting outside it's operational boundary.
Audit Procedure
Command Line
Review the /etc/rsyslog.conf and /etc/rsyslog.d/*.conf files and verify that the system is not configured to accept incoming logs.
Old format:
grep '$ModLoad imtcp' /etc/rsyslog.conf /etc/rsyslog.d/*.conf
grep '$InputTCPServerRun' /etc/rsyslog.conf /etc/rsyslog.d/*.conf
No output expected.
New format:
grep -P -- '^\h*module\(load="imtcp"\)' /etc/rsyslog.conf /etc/rsyslog.d/*.conf
grep -P -- '^\h*input\(type="imtcp" port="514"\)' /etc/rsyslog.conf /etc/rsyslog.d/*.conf
No output expected.
Expected Result
No output should be returned for any of the commands.
Remediation
Command Line
Remove or comment out any lines in /etc/rsyslog.conf and /etc/rsyslog.d/*.conf that configure rsyslog to accept incoming logs. Restart the service:
systemctl restart rsyslog
Default Value
rsyslog is not configured to receive logs from remote clients by default.
References
- NIST SP 800-53 Rev. 5: AU-2, AU-12, CM-6, CM-7
CIS Controls
| Controls Version | Control |
|---|---|
| v8 | 4.8 Uninstall or Disable Unnecessary Services on Enterprise Assets and Software - Uninstall or disable unnecessary services on enterprise assets and software. |
| v8 | 8.2 Collect Audit Logs - Collect audit logs. Ensure that logging, per the enterprise's audit log management process, has been enabled across enterprise assets. |
| v7 | 6.2 Activate audit logging - Ensure that local logging has been enabled on all systems and networking devices. |
| v7 | 6.3 Enable Detailed Logging - Enable system logging to include detailed information such as an event source, date, user, timestamp, source addresses, destination addresses, and other useful elements. |
| v7 | 9.2 Ensure Only Approved Ports, Protocols and Services Are Running - Ensure that only network ports, protocols, and services listening on a system with validated business needs, are running on each system. |