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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-204629	RHEL-07-040820	SV-204629r603261_rule		Medium

Description
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).

STIG	Date
Red Hat Enterprise Linux 7 Security Technical Implementation Guide	2020-12-08

Details

Check Text ( C-4753r89079_chk )
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.

Check Text ( C-4753r89079_chk )

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 (F-4753r89080_fix)
Remove all unapproved tunnels from the system, or document them with the ISSO.