The system must not respond to ICMPv6 echo requests sent to a broadcast address.

From SUSE Linux Enterprise Server v11 for System z

Associated with: CCI-000366

SV-45993r1_rule The system must not respond to ICMPv6 echo requests sent to a broadcast address.

Vulnerability discussion

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

Check content

Check for an ip6tables rule that drops inbound IPv6 ICMP ECHO_REQUESTs sent to the all-hosts multicast address. Procedure: # less /etc/sysconfig/scripts/SuSEfirewall2-custom Check for a rule in, or referenced by, the INPUT chain such as: ip6tables -A INPUT -p icmpv6 -d ff02::1 --icmpv6-type 128 -j DROP If such a rule does not exist, this is a finding.

Fix text

Add an ip6tables rule that drops inbound IPv6 ICMP ECHO_REQUESTs sent to the all-hosts multicast address. Edit /etc/sysconfig/scripts/SuSEfirewall2-custom and add a rule in, or referenced by, the INPUT chain such as: ip6tables -A INPUT -p icmpv6 -d ff02::1 --icmpv6-type 128 -j DROP Reload the SuSEfirewall2 rules. Procedure: # rcSuSEfirewall2 restart

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