3.5.3.3.2 Ensure IPv6 loopback traffic is configured - OUTPUT

Information

Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network (::1).

Rationale:

Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network (::1) traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.

Note: Changing firewall settings while connected over network can result in being locked out of the system.

Solution

Run the following commands to implement the loopback rules:

# ip6tables -A INPUT -i lo -j ACCEPT
# ip6tables -A OUTPUT -o lo -j ACCEPT
# ip6tables -A INPUT -s ::1 -j DROP

See Also

https://workbench.cisecurity.org/files/2925

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12), CSCv7|9.4

Plugin: Unix

Control ID: c6da6e09a8d42f07c55ab7a03699ca4d7d541b82c4f86370ed335b69aebed5ca