Title

The SUSE operating system must not respond to Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) echoes sent to a broadcast address. (Cat II impact)

Discussion

Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.

Check Content

Verify the SUSE operating system does not accept IPv4 source-routed packets. Check the value of the accept source route variable with the following command: # sysctl net.ipv4.icmp_echo_ignore_broadcasts net.ipv4.icmp_echo_ignore_broadcasts = 1 If the returned line does not have a value of "1" this is a finding.

Fix Text

Configure the SUSE operating system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" (or modify the line to have the required value): net.ipv4.icmp_echo_ignore_broadcasts = 1 Run the following command to apply this value: # sysctl --system

Additional Identifiers

Rule ID: SV-217290r603262_rule

Vulnerability ID: V-217290

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

CCIs tied to check.

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