Detections
Analytics

1.191 RHEL-09-253055

Information

RHEL 9 must not respond to Internet Control Message Protocol (ICMP) echoes sent to a broadcast address.

GROUP ID: V-257966
RULE ID: SV-257966r991589

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

Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.

Solution

Configure RHEL 9 to not respond to IPv4 ICMP echoes sent to a broadcast address.

Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:

net.ipv4.icmp_echo_ignore_broadcasts = 1

Load settings from all system configuration files with the following command:

$ sudo sysctl --system

See Also

https://workbench.cisecurity.org/benchmarks/22008

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-257966r991589_rule, STIG-ID|RHEL-09-253055, Vuln-ID|V-257966

Plugin: Unix

Control ID: 2b6830ace6d03014ef73b45c7113f96668a5af02c538c1eb1744d294c732d558