TOSS 5 must not forward Internet Protocol version 4 (IPv4) source-routed packets.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-282686 | TOSS-05-000214 | SV-282686r1201038_rule | CCI-000366 | medium |
| Description | ||||
| Source-routed packets allow the source of the packet to suggest 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 IPv4 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv4 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-282686r1201038_chk)
Verify TOSS 5 will not accept IPv4 source-routed packets using the following command:
$ sudo sysctl net.ipv4.conf.all.accept_source_route
net.ipv4.conf.all.accept_source_route = 0
If "net.ipv4.conf.all.accept_source_route" is not set to "0", or a line is not returned, this is a finding.
Fix Text (F-87152r1201037_fix)
Configure TOSS 5 to ignore IPv4 source-routed packets.
Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:
net.ipv4.conf.all.accept_source_route = 0
Load settings from all system configuration files using the following command:
$ sudo sysctl --system