STIGQter: STIG Summary: Red Hat Enterprise Linux 7 Security Technical Implementation Guide Version: 3 Release: 3 Benchmark Date: 23 Apr 2021:

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.

DISA Rule

SV-204613r603261_rule

Vulnerability Number

V-204613

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-07-040630

Severity

CAT II

CCI(s)

• CCI-000366 - The organization implements the security configuration settings.

Weight

10

Fix Recommendation

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

Check Contents

Verify the system does not respond to IPv4 ICMP echoes sent to a broadcast address.

# grep net.ipv4.icmp_echo_ignore_broadcasts /etc/sysctl.conf /etc/sysctl.d/*

If " net.ipv4.icmp_echo_ignore_broadcasts" is not configured in the /etc/sysctl.conf file or in the /etc/sysctl.d/ directory, is commented out, or does not have a value of "1", this is a finding.

Check that the operating system implements the "icmp_echo_ignore_broadcasts" variable with the following command:

# /sbin/sysctl -a | grep 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-204613

Documentable

False

Rule Version

RHEL-07-040630

Severity Override Guidance

Verify the system does not respond to IPv4 ICMP echoes sent to a broadcast address.

# grep net.ipv4.icmp_echo_ignore_broadcasts /etc/sysctl.conf /etc/sysctl.d/*

If " net.ipv4.icmp_echo_ignore_broadcasts" is not configured in the /etc/sysctl.conf file or in the /etc/sysctl.d/ directory, is commented out, or does not have a value of "1", this is a finding.

Check that the operating system implements the "icmp_echo_ignore_broadcasts" variable with the following command:

# /sbin/sysctl -a | grep 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

2899

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