The system must ignore IPv6 Internet Control Message Protocol (ICMP ) redirect messages.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22550	GEN007860	SV-35241r1_rule	ECSC-1	Medium

Description
ICMP redirect messages are used by routers to inform hosts of a more direct route existing for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.

STIG	Date
HP-UX 11.23 Security Technical Implementation Guide	2015-12-02

Details

Check Text ( C-35088r1_chk )
Determine if the system blocks inbound IPv6 ICMP redirects. # ipfstat -6 -i Check for a rule such as: block in quick proto icmpv6 from any to any icmpv6-type 137 If a rule blocking inbound IPv6 ICMP redirects does not exist, this is a finding.

Fix Text (F-30359r1_fix)
Add an IPF rule to block inbound IPv6 ICMP redirect packets. Edit /etc/opt/ipf/ipf6.conf and add a rule such as: block in quick proto icmpv6 from any to any icmpv6-type 137 Reload the IPF rules. # ipf -6 -Fa -A -f /etc/opt/ipf/ipf6.conf