STIGQter: STIG Summary: Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide Version: 1 Release: 7 Benchmark Date: 01 Jul 2026:

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

DISA Rule

SV-269248r1050130_rule

Vulnerability Number

V-269248

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

ALMA-09-019050

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

Configure AlmaLinux OS 9 to use reverse path filtering on all IP interfaces.

Create a numbered *.conf file in /etc/sysctl.d/ with the following content:

net.ipv4.icmp_echo_ignore_broadcasts = 1

The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command:

$ sysctl –system

Check Contents

Verify AlmaLinux OS 9 does not respond to ICMP echoes sent to a broadcast address 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.

Vulnerability Number

V-269248

Documentable

False

Rule Version

ALMA-09-019050

Severity Override Guidance

Verify AlmaLinux OS 9 does not respond to ICMP echoes sent to a broadcast address 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.

Check Content Reference

M

Target Key

5664