Title

The system must not forward IPv4 source-routed packets. (Cat II impact)

Discussion

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.

Check Content

Determine the type of zone that you are currently securing. # zonename If the zone is not the global zone, determine if any interfaces are exclusive to the zone: # dladm show-link If the output indicates "insufficient privileges" then this requirement is not applicable. If the zone is the global zone or the non-global zone has exclusive interfaces verify the network settings: # ndd /dev/ip ip_forward_src_routed If the returned value is not 0, this is a finding.

Fix Text

Configure the system to not forward IPv4 source-routed packets. Procedure: # ndd /dev/ip ip_forward_src_routed 0 This command must also be added to a system startup script.

Additional Identifiers

Rule ID: SV-226888r603265_rule

Vulnerability ID: V-226888

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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