The system must ignore IPv4 ICMP redirect messages.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22416	GEN003609	SV-26630r2_rule		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
SOLARIS 10 SPARC SECURITY TECHNICAL IMPLEMENTATION GUIDE	2016-06-22

Details

Check Text ( C-27667r2_chk )
Determine the type of zone that you are currently securing. # zonename If the zone is not the global zone, determine if any interfaces are exclusive to the zone: # dladm show-link If the output indicates "insufficient privileges" then this requirement is not applicable. If the zone is the global zone or the non-global zone has exclusive interfaces verify the system does not accept IPv4 ICMP redirect messages. Procedure: # ndd -get /dev/ip ip_ignore_redirect If the result is not 1, this is a finding.

Check Text ( C-27667r2_chk )

Determine the type of zone that you are currently securing.
# zonename

If the zone is not the global zone, determine if any interfaces are exclusive to the zone:
# dladm show-link

If the output indicates "insufficient privileges" then this requirement is not applicable.

If the zone is the global zone or the non-global zone has exclusive interfaces verify the system does not accept IPv4 ICMP redirect messages.

Procedure:
# ndd -get /dev/ip ip_ignore_redirect

If the result is not 1, this is a finding.

Fix Text (F-23873r1_fix)
Configure the system to not accept IPv4 ICMP redirect messages. Procedure: # ndd -set /dev/ip ip_ignore_redirect 1 This command must also be added to a system startup script.