Title

The system must not respond to ICMPv6 echo requests sent to a broadcast address. (Cat II impact)

Discussion

Responding to broadcast ICMP echo requests facilitates network mapping and provides a vector for amplification attacks.

Check Content

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 determine if the system is configured to ignore IPv6 multicast ICMP echo-requests. Procedure: # ndd -get /dev/ip ip6_respond_to_echo_multicast If the result is not 0, this is a finding.

Fix Text

Configure the system to not respond to IPv6 multicast ICMP echo-requests. Procedure: # ndd -set /dev/ip ip6_respond_to_echo_multicast 0 This command must also be added to a system startup script.

Additional Identifiers

Rule ID: SV-227967r603266_rule

Vulnerability ID: V-227967

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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