Title

The system must not send IPv4 ICMP redirects. (Cat II impact)

Discussion

ICMP redirect messages are used by routers to inform hosts of a more direct route existing for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.

Check Content

Open a terminal session and enter the following command to view the value of "net.inet.ip.redirect". sysctl -a | grep net.inet.ip.redirect If the value of "net.inet.ip.redirect" is not set to "0", this is a finding.

Fix Text

Open a terminal session and edit the /etc/sysctl.conf file and add the following line. net.inet.ip.redirect=0 NOTE: If the sysctl.conf file does not exist use the following command to create one. touch /etc/sysctl.conf

Additional Identifiers

Rule ID: SV-38205r1_rule

Vulnerability ID: V-22417

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.