STIGQter: STIG Summary: Oracle Linux 9 Security Technical Implementation Guide Version: 1 Release: 6 Benchmark Date: 01 Jul 2026:

OL 9 must prevent IPv4 Internet Control Message Protocol (ICMP) redirect messages from being accepted.

DISA Rule

SV-271869r1092319_rule

Vulnerability Number

V-271869

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

OL09-00-006025

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

Configure OL 9 to prevent IPv4 ICMP redirect messages from being accepted.

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

net.ipv4.conf.default.accept_redirects = 0

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

$ sudo sysctl --system

Check Contents

Verify that OL 9 will not accept IPv4 ICMP redirect messages.

Check the value of the default "accept_redirects" variables with the following command:

$ sysctl net.ipv4.conf.default.accept_redirects
net.ipv4.conf.default.accept_redirects = 0

If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding.

Vulnerability Number

V-271869

Documentable

False

Rule Version

OL09-00-006025

Severity Override Guidance

Verify that OL 9 will not accept IPv4 ICMP redirect messages.

Check the value of the default "accept_redirects" variables with the following command:

$ sysctl net.ipv4.conf.default.accept_redirects
net.ipv4.conf.default.accept_redirects = 0

If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding.

Check Content Reference

M

Target Key

5680