Cis Ubuntu1804 V220 5 1 2 6

5.1.2.6 Ensure rsyslog is configured to send logs to a remote log host (Manual)

Profile

• Level: 1 - Server
• Level: 1 - Workstation
• Assessment Status: Manual

Description

RSyslog supports the ability to send log events it gathers to a remote log host or to receive messages from remote hosts, thus enabling centralised log management.

Rationale

Storing log data on a remote host protects log integrity from local attacks. If an attacker gains root access on the local system, they could tamper with or remove log data that is stored on the local system.

Audit Procedure

Command Line

Review the /etc/rsyslog.conf and /etc/rsyslog.d/*.conf files and verify that logs are sent to a central host (where loghost.example.com is the name of your central log host):

Old format:

grep "*.*[^I][^I]*@" /etc/rsyslog.conf /etc/rsyslog.d/*.conf

Output should include @@<FQDN or IP of remote loghost>, for example:

*.* @@loghost.example.com

New format:

grep -E '^\s*([^#]+\s+)?action\(([^#]+\s+)?\btarget=\"?[^#"]+\"?\b' /etc/rsyslog.conf /etc/rsyslog.d/*.conf

Output should include target=<FQDN or IP of remote loghost>, for example:

*.* action(type="omfwd" target="loghost.example.com" port="514" protocol="tcp"

Expected Result

Output should show logs being sent to a remote host.

Remediation

Command Line

Edit the /etc/rsyslog.conf and /etc/rsyslog.d/*.conf files and add the following line (where loghost.example.com is the name of your central log host). The target directive may either be a fully qualified domain name or an IP address.

*.* action(type="omfwd" target="192.168.2.100" port="514" protocol="tcp"
       action.resumeRetryCount="100"
         queue.type="LinkedList" queue.size="1000")

Run the following command to reload the rsyslogd configuration:

systemctl restart rsyslog

Default Value

Logs are not sent to a remote host by default.

References

1. See the rsyslog.conf(5) man page for more information.
2. NIST SP 800-53 Rev. 5: AU-6

CIS Controls