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

From Oracle Linux 5 Security Technical Implementation Guide

Associated with: CCI-000366

SV-63385r1_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 iptables rule that drops inbound IPv6 ICMP ECHO_REQUESTs sent to the all-hosts multicast address. Procedure: # less /etc/sysconfig/ip6tables Check for a rule in, or referenced by, the INPUT chain such as: -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 iptables rule that drops inbound IPv6 ICMP ECHO_REQUESTs sent to the all-hosts multicast address. Edit /etc/sysconfig/ip6tables and add a rule in, or referenced by, the INPUT chain such as: -A INPUT -p icmpv6 -d ff02::1 --icmpv6-type 128 -j DROP Reload the iptables rules. Procedure: # service ip6tables restart

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