Title

RHEL 9 must not have unauthorized IP tunnels configured. (Cat II impact)

Discussion

IP tunneling mechanisms can be used to bypass network filtering. If tunneling is required, it must be documented with the information system security officer (ISSO).

Check Content

Verify that RHEL 9 does not have unauthorized IP tunnels configured. Determine if the "IPsec" service is active with the following command: $ systemctl is-active ipsec Inactive If the "IPsec" service is active, check for configured IPsec connections ("conn"), with the following command: $ sudo grep -rni conn /etc/ipsec.conf /etc/ipsec.d/ Verify any returned results are documented with the ISSO. If the IPsec tunnels are active and not approved, this is a finding.

Fix Text

Remove all unapproved tunnels from the system, or document them with the ISSO.

Additional Identifiers

Rule ID: SV-257950r1045006_rule

Vulnerability ID: V-257950

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.