The IPS must block malicious Internet Control Message Protocol (ICMP) packets by properly configuring ICMP signatures and rules.

ICMP messages are used to provide feedback about problems in the network. These messages are sent back to the sender to support diagnostics; however, some messages can also provide host information, network topology, and a covert channel that may be exploited by an attacker.

Given the prevalence of ICMP traffic on the network, monitoring for malicious ICMP traffic would be cumbersome. Vendors provide signatures and rules which filter for known ICMP traffic exploits.

If the device being reviewed is an IDS, this is not applicable.

Verify the IPS blocks malicious ICMP packets by properly configuring ICMP signatures and rules.

If the IPS does not block malicious ICMP packets by properly configuring ICMP signatures and rules, this is a finding.

Configure the IPS to block malicious ICMP packets by properly configuring ICMP signatures and rules.