The systems local IPv6 firewall must implement a deny-all, allow-by-exception policy for inbound packets.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-38444	RHEL-06-000523	SV-50244r2_rule		Medium

Description
In "ip6tables" the default policy is applied only after all the applicable rules in the table are examined for a match. Setting the default policy to "DROP" implements proper design for a firewall, i.e., any packets which are not explicitly permitted should not be accepted.

STIG	Date
Red Hat Enterprise Linux 6 Security Technical Implementation Guide	2015-05-26

Details

Check Text ( C-45999r2_chk )
If IPv6 is disabled, this is not applicable. Inspect the file "/etc/sysconfig/ip6tables" to determine the default policy for the INPUT chain. It should be set to DROP: # grep ":INPUT" /etc/sysconfig/ip6tables If the default policy for the INPUT chain is not set to DROP, this is a finding.

Fix Text (F-43389r3_fix)
To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in "/etc/sysconfig/ip6tables": :INPUT DROP [0:0] Restart the IPv6 firewall: # service ip6tables restart