AlmaLinux OS 9 must not forward source-routed packets.
An XCCDF Rule
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 IP forwarding is enabled and the system is functioning as a router. Accepting source-routed packets has few legitimate uses. It must be disabled unless it is absolutely required.
- ID
- SV-269259r1050141_rule
- Version
- ALMA-09-020260
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Configure AlmaLinux OS 9 to ignore source-routed packets.
Create a numbered *.conf file in /etc/sysctl.d/ with the following content:
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0