Title

The system must not apply reversed source routing to TCP responses. (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.

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 system does not apply reversed source routing to TCP responses. # ndd /dev/tcp tcp_rev_src_routes If the result is not 0, this is a finding.

Fix Text

Configure the system to not apply reversed source routing to TCP responses. # ndd -set /dev/tcp tcp_rev_src_routes 0 Also add this command to a system startup script.

Additional Identifiers

Rule ID: SV-226893r603265_rule

Vulnerability ID: V-226893

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.