Information
The operating system must be configured so that the rsyslog daemon does not accept log messages from other servers unless the server is being used for log aggregation.
Rationale:
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 itself, could introduce misleading information in to the system's logs, or could 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 Authorizing Official.
Solution
Modify the /etc/rsyslog.conf file to remove the ModLoad imudp, and ModLoad imrelp configuration lines, or document the system as being used for log aggregation.
Example: vim /etc/rsyslog.conf
Remove or comment out these following configuration lines:
#ModLoad imudp
#ModLoad imrelp
Notes:
This Benchmark recommendation maps to:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide:
Version 2, Release: 3 Benchmark Date: 26 Apr 2019
Vul ID: V-72211
Rule ID: SV-86835r2_rule
STIG ID: RHEL-07-031010
Severity: CAT II