The SUSE operating system must not send Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirects.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-217295 | SLES-12-030420 | SV-217295r991589_rule | CCI-000366 | medium |
| Description | ||||
| ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table, possibly revealing portions of the network topology. | ||||
| STIG | Date | |||
| SUSE Linux Enterprise Server 12 Security Technical Implementation Guide | 2025-05-14 | |||
Details
Check Text (C-217295r991589_chk)
Verify the SUSE operating system does not send IPv4 ICMP redirect messages.
Check the value of the "all send_redirects" variables with the following command:
# sysctl net.ipv4.conf.all.send_redirects
net.ipv4.conf.all.send_redirects =0
If the returned line does not have a value of "0” this is a finding.
Fix Text (F-18521r370042_fix)
Configure the SUSE operating system to not allow interfaces to perform IPv4 ICMP redirects.
Set the system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" (or modify the line to have the required value):
net.ipv4.conf.all.send_redirects=0
Run the following command to apply this value:
# sysctl --system