RHEL 10 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-281355 | RHEL-10-800230 | SV-281355r1167215_rule | CCI-002385 | medium |
| Description | ||||
| An illicit ICMP redirect message could result in a man-in-the-middle attack. Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00086 | ||||
| STIG | Date | |||
| Red Hat Enterprise Linux 10 Security Technical Implementation Guide | 2026-03-11 | |||
Details
Check Text (C-281355r1167215_chk)
Note: If IPv6 is disabled on the system, this requirement is not applicable.
Verify RHEL 10 ignores IPv6 ICMP redirect messages.
Check the value of the "net.ipv6.conf.all.accept_redirects" variable with the following command:
$ sysctl net.ipv6.conf.all.accept_redirects
net.ipv6.conf.all.accept_redirects = 0
If "net.ipv6.conf.all.accept_redirects" is not set to "0" or is missing, this is a finding.
Fix Text (F-85821r1167214_fix)
Configure RHEL 10 to ignore Internet Protocol version 6 (IPv6) ICMP redirect messages.
Create a configuration file if it does not already exist:
$ sudo vi /etc/sysctl.d/ipv6_accept_redirects.conf
Add the following line to the file:
net.ipv6.conf.all.accept_redirects = 0
Reload settings from all system configuration files with the following command:
$ sudo sysctl --system