TOSS 5 must not accept router advertisements on all Internet Protocol version 6 (IPv6) interfaces.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-282698 | TOSS-05-000226 | SV-282698r1201350_rule | CCI-000366 | medium |
| Description | ||||
| An illicit router advertisement message could result in a man-in-the-middle attack. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide | 2026-04-01 | |||
Details
Check Text (C-282698r1201350_chk)
Verify TOSS 5 does not accept router advertisements on all IPv6 interfaces, unless the system is a router.
Note: If IPv6 is disabled on the system, this requirement is not applicable.
Determine if router advertisements are not accepted by using the following command:
$ sudo sysctl net.ipv6.conf.all.accept_ra
net.ipv6.conf.all.accept_ra = 0
If the "accept_ra" value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.
Fix Text (F-87164r1201073_fix)
Configure TOSS 5 to not accept router advertisements on all IPv6 interfaces unless the system is a router.
Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:
net.ipv6.conf.all.accept_ra = 0
Load settings from all system configuration files using the following command:
$ sudo sysctl --system