OL 9 must not forward IPv6 source-routed packets.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-271879 | SRG-OS-000480-GPOS-00227 | OL09-00-006042 | SV-271879r1092349_rule | 2025-05-08 | 1 |
| 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. |
| ℹ️ Check |
|---|
| Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Verify that OL 9 does not accept IPv6 source-routed packets. Check the value of the accept source route variable with the following command: $ sysctl net.ipv6.conf.all.accept_source_route net.ipv6.conf.all.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. |
| ✔️ Fix |
|---|
| Configure OL 9 to not forward IPv6 source-routed packets. Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_source_route = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |