The SUSE operating system must not forward Internet Protocol version 6 (IPv6) source-routed packets by default.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-235017 | SLES-15-040321 | SV-235017r991589_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 IPv4 forwarding is enabled and the system is functioning as a router. | ||||
| STIG | Date | |||
| SUSE Linux Enterprise Server 15 Security Technical Implementation Guide | 2025-05-14 | |||
Details
Check Text (C-235017r991589_chk)
Verify the SUSE operating system does not accept IPv6 source-routed packets by default.
Check the value of the default IPv6 accept source route variable with the following command:
> sudo sysctl net.ipv6.conf.default.accept_source_route
net.ipv6.conf.default.accept_source_route = 0
If the network parameter "ipv6.conf.default.accept_source_route" is not equal to "0" or nothing is returned, this is a finding.
Fix Text (F-38168r619321_fix)
Configure the SUSE operating system to disable IPv6 default source routing by running the following command as an administrator:
> sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
If "0" is not the system's default value, add or update the following line in "/etc/sysctl.d/99-stig.conf":
> sudo sh -c 'echo "net.ipv6.conf.default.accept_source_route=0" >> /etc/sysctl.d/99-stig.conf'
> sudo sysctl --system