SLEM 5 must not forward Internet Protocol version 4 (IPv4) source-routed packets.
An XCCDF Rule
Description
<VulnDiscussion>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/IPv6 forwarding is enabled and the system is functioning as a router.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-261313r996409_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure SLEM 5 to disable IPv4 source routing by running the following command as an administrator:
> sudo sysctl -w net.ipv4.conf.all.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":