The SUSE operating system must not allow interfaces to send Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages by default.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-235022 | SLES-15-040360 | SV-235022r991589_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 contain information from the system's route table, possibly revealing portions of the network topology. |
| STIG | Date |
| SUSE Linux Enterprise Server 15 Security Technical Implementation Guide | 2025-05-14 |
Details
| Check Text (C-38210r619335_chk) |
| Verify the SUSE operating system does not allow interfaces to perform IPv4 ICMP redirects by default. Check the value of the default IPv4 send_redirects variable with the following command: > sudo sysctl net.ipv4.conf.default.send_redirects net.ipv4.conf.default.send_redirects = 0 If the network parameter "ipv4.conf.default.send_redirects" is not equal to "0" or nothing is returned, this is a finding. |
| Fix Text (F-38173r619336_fix) |
| Configure the SUSE operating system to not allow interfaces to perform IPv4 ICMP redirects by default by running the following command as an administrator: > sudo sysctl -w net.ipv4.conf.default.send_redirects=0 If "0" is not the system's default value, add or update the following line in "/etc/sysctl.d/99-stig.conf": > sudo sh -c 'echo "net.ipv4.conf.default.send_redirects=0" >> /etc/sysctl.d/99-stig.conf' > sudo sysctl --system |