The system must ignore ICMPv4 bogus error responses.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-38537	RHEL-06-000093	SV-50338r3_rule		Low

Description
Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.

STIG	Date
Red Hat Enterprise Linux 6 Security Technical Implementation Guide	2020-05-19

Details

Check Text ( C-46095r3_chk )
The status of the "net.ipv4.icmp_ignore_bogus_error_responses" kernel parameter can be queried by running the following command: $ sysctl net.ipv4.icmp_ignore_bogus_error_responses net.ipv4.icmp_ignore_bogus_error_responses = 1 $ grep net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf /etc/sysctl.d/* net.ipv4.icmp_ignore_bogus_error_responses = 1 If "net.ipv4.icmp_ignore_bogus_error_responses" 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 Text ( C-46095r3_chk )

The status of the "net.ipv4.icmp_ignore_bogus_error_responses" kernel parameter can be queried by running the following command:

$ sysctl net.ipv4.icmp_ignore_bogus_error_responses
net.ipv4.icmp_ignore_bogus_error_responses = 1

$ grep net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf /etc/sysctl.d/*
net.ipv4.icmp_ignore_bogus_error_responses = 1

If "net.ipv4.icmp_ignore_bogus_error_responses" 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.

Fix Text (F-43485r2_fix)
To set the runtime status of the "net.ipv4.icmp_ignore_bogus_error_responses" kernel parameter, run the following command: # sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1 Set the system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" or a config file in the /etc/sysctl.d/ directory (or modify the line to have the required value): net.ipv4.icmp_ignore_bogus_error_responses = 1 Issue the following command to make the changes take effect: # sysctl --system

Fix Text (F-43485r2_fix)

To set the runtime status of the "net.ipv4.icmp_ignore_bogus_error_responses" kernel parameter, run the following command:

# sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1

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

net.ipv4.icmp_ignore_bogus_error_responses = 1

Issue the following command to make the changes take effect:

# sysctl --system