The Red Hat Enterprise Linux operating system must not have unauthorized IP tunnels configured.

From Red Hat Enterprise Linux 7 Security Technical Implementation Guide

Associated with: CCI-000366

SV-86941r2_rule The Red Hat Enterprise Linux operating system must not have unauthorized IP tunnels configured.

Vulnerability 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 the system does not have unauthorized IP tunnels configured. Check to see if "libreswan" is installed with the following command: # yum list installed libreswan libreswan.x86-64 3.20-5.el7_4 If "libreswan" is installed, check to see if the "IPsec" service is active with the following command: # systemctl status ipsec ipsec.service - Internet Key Exchange (IKE) Protocol Daemon for IPsec Loaded: loaded (/usr/lib/systemd/system/ipsec.service; disabled) Active: inactive (dead) If the "IPsec" service is active, check to see if any tunnels are configured in "/etc/ipsec.conf" and "/etc/ipsec.d/" with the following commands: # grep -iw conn /etc/ipsec.conf /etc/ipsec.d/*.conf If there are indications that a "conn" parameter is configured for a tunnel, ask the System Administrator if the tunnel is documented with the ISSO. If "libreswan" is installed, "IPsec" is active, and an undocumented tunnel is active, this is a finding.

Fix text

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

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