TOSS 5 must not forward Internet Protocol version 6 (IPv6) source-routed packets by default.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-282704 | TOSS-05-000232 | SV-282704r1201359_rule | CCI-000366 | medium |
| Description | ||||
| Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It must be disabled unless it is absolutely required. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide | 2026-04-01 | |||
Details
Check Text (C-282704r1201359_chk)
Verify TOSS 5 does not accept IPv6 source-routed packets by default.
Note: If IPv6 is disabled on the system, this requirement is not applicable.
Check the value of the accept source route variable using the following command:
$ sudo sysctl net.ipv6.conf.default.accept_source_route
net.ipv6.conf.default.accept_source_route = 0
If the returned line does not have a value of "0", or a line is not returned, this is a finding.
Fix Text (F-87170r1201091_fix)
Configure TOSS 5 to not forward IPv6 source-routed packets by default.
Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:
net.ipv6.conf.default.accept_source_route = 0
Load settings from all system configuration files using the following command:
$ sudo sysctl --system