RHEL-07-040630 - The Red Hat Enterprise Linux operating system must not respond to Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) echoes sent to a broadcast address.

Information

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

Solution

Set the system to the required kernel parameter by adding the following line to '/etc/sysctl.conf' or a configuration file in the /etc/sysctl.d/ directory (or modify the line to have the required value):

net.ipv4.icmp_echo_ignore_broadcasts = 1

Issue the following command to make the changes take effect:

# sysctl --system

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_7_V3R15_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-204613r991589_rule, STIG-ID|RHEL-07-040630, STIG-Legacy|SV-86911, STIG-Legacy|V-72287, Vuln-ID|V-204613

Plugin: Unix

Control ID: 701ed944936a6454505efb528720128bb73cdb97230b08810db192b2a733a2ad