The system must ignore IPv4 ICMP redirect messages.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22416	GEN003609 M6	SV-38204r1_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
MAC OSX 10.6 Workstation Security Technical Implementation Guide Draft	2013-01-10

Details

Check Text ( C-37661r1_chk )
Open a terminal session and enter the following command to view the value of "net.inet.icmp.drop_redirect". sysctl -a | grep net.inet.icmp.drop_redirect If the value of "net.inet.icmp.drop_redirect" is not set to "0", this is a finding.

Fix Text (F-32902r1_fix)
Open a terminal session and edit the /etc/sysctl.conf file and add the following line. net.inet.icmp.drop_redirect=0 NOTE: If the sysctl.conf file does not exist use the following command to create one. touch /etc/sysctl.conf