GEN003603 - The system must not respond to Internet Control Message Protocol v4 (ICMPv4) echoes sent to a broadcast address.

Information

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

Solution

Configure the system to not respond to ICMP ECHO_REQUESTs sent to broadcast addresses. Edit /etc/sysctl.conf and add a setting for 'net.ipv4.icmp_echo_ignore_broadcasts=1' and reload the sysctls.

Procedure:
# echo 'net.ipv4.icmp_echo_ignore_broadcasts=1' >> /etc/sysctl.conf
# sysctl -p

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Oracle_Linux_5_V1R14_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|CM-6, 800-53|SC-7(12), CAT|II, CCI|CCI-001551, Rule-ID|SV-64459r1_rule, STIG-ID|GEN003603, Vuln-ID|V-22410

Plugin: Unix

Control ID: 4b5de43b357d7cdfd5949e04f287ce65c7ca2ecc9812e93d4f8b310641f65be8