Changes are coming to https://stigviewer.com.
Take our survey to help us understand your usage and how we can better serve you in the future.
Take Survey
The Red Hat Enterprise Linux operating system must prevent Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages from being accepted.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-204614 | RHEL-07-040640 | SV-204614r603261_rule | Medium |
| Description |
|---|
| ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. |
| STIG | Date |
|---|---|
| Red Hat Enterprise Linux 7 Security Technical Implementation Guide | 2021-03-01 |
Details
| Check Text ( C-4738r89034_chk ) |
|---|
| Verify the system will not accept IPv4 ICMP redirect messages. # grep 'net.ipv4.conf.default.accept_redirects' /etc/sysctl.conf /etc/sysctl.d/* If " net.ipv4.conf.default.accept_redirects " 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 "0", this is a finding. Check that the operating system implements the value of the "accept_redirects" variables with the following command: # /sbin/sysctl -a | grep 'net.ipv4.conf.default.accept_redirects' net.ipv4.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", this is a finding. |
| Fix Text (F-4738r89035_fix) |
|---|
| Set the system to not accept IPv4 ICMP redirect messages 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.conf.default.accept_redirects = 0 Issue the following command to make the changes take effect: # sysctl --system |