The system must ignore ICMPv4 bogus error responses.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-38537	RHEL-06-000093	SV-50338r2_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	2016-06-05

Details

Check Text ( C-46095r2_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 The output of the command should indicate a value of "1". If this value is not the default value, investigate how it could have been adjusted at runtime, and verify it is not set improperly in "/etc/sysctl.conf". $ grep net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf If the correct value is not returned, this is a finding.

Check Text ( C-46095r2_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

The output of the command should indicate a value of "1". If this value is not the default value, investigate how it could have been adjusted at runtime, and verify it is not set improperly in "/etc/sysctl.conf".

$ grep net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf

If the correct value is not returned, this is a finding.

Fix Text (F-43485r1_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 If this is not the system's default value, add the following line to "/etc/sysctl.conf": net.ipv4.icmp_ignore_bogus_error_responses = 1