Title

The Juniper PE router must be configured to ignore or block all packets with any IP options. (Cat II impact)

Discussion

Packets with IP options are not fast switched and therefore must be punted to the router processor. Hackers who initiate denial-of-service (DoS) attacks on routers commonly send large streams of packets with IP options. Dropping the packets with IP options reduces the load of IP options packets on the router. The end result is a reduction in the effects of the DoS attack on the router and on downstream routers.

Check Content

Review the router configuration to determine if it will block all packets with IP options. firewall { family inet { filter INGRESS_FILTER { term BLOCK_TO_CORE { from { destination-address { x.x.x.x/8; } } then { log; discard; } } term BLOCK_IP_OPTIONS { from { ip-options any; } then { discard; } } term ALLOW_TRANSIT_TRAFFIC { then accept; } } } If the router is not configured to drop all packets with IP options, this is a finding.

Fix Text

Configure the router to drop all packets with IP options. [edit firewall family inet filter INGRESS_FILTER] set term BLOCK_IP_OPTIONS from ip-options any set term BLOCK_IP_OPTIONS then discard insert term BLOCK_IP_OPTIONS before term ALLOW_TRANSIT_TRAFFIC

Additional Identifiers

Rule ID: SV-217078r945860_rule

Vulnerability ID: V-217078

Group Title: SRG-NET-000205-RTR-000016

Expert Comments

CCIs tied to check.

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