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The system must ignore IPv4 ICMP redirect messages.


Overview

Finding ID Version Rule ID IA Controls Severity
V-22416 GEN003609 SV-29719r1_rule ECSC-1 Medium
Description
ICMP redirect messages are used by routers to inform hosts that a more direct route exists 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 2013-07-02

Details

Check Text ( C-36510r1_chk )
Determine if the system is configured to block inbound IPv4 ICMP redirect
messages.
# ipfstat -i

Examine the list for a rule such as:
block in quick proto icmp from any to any icmp-type redir

If the listed rules do not block inbound IPv4 ICMP redirect messages,
this is a finding.
Fix Text (F-31870r1_fix)
Edit /etc/opt/ipf/ipf.conf and add rules to block incoming
IPv4 ICMP redirect messages, such as:
block in quick proto icmp from any to any icmp-type redir

Reload the IPF rules. Flush the rules from your ruleset using the -Fa option.
The -A option specifies the active rules list. The -f option specifies the rules
configuration file to be used:

# ipf -Fa -A -f /etc/opt/ipf/ipf.conf