Detections
Analytics

1.40 CISC-RT-000398

Information

The Cisco perimeter router must be configured to drop IPv6 packets containing a Hop-by-Hop or Destination Option extension header with an undefined option type.

GROUP ID: V-230160RULE ID: SV-230160r856675

The optional and extensible natures of the IPv6 extension headers require higher scrutiny since many implementations do not always drop packets with headers that it cannot recognize, and hence could cause a Denial-of-Service on the target device. In addition, the type, length, value (TLV) formatting provides the ability for headers to be very large.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Configure the router to drop all inbound IPv6 packets containing an undefined option type value regardless of whether they appear in a Hop-by-Hop or Destination Option header as shown in the example below.

RP/0/0/CPU0:R3(config)# ipv6 access-list FILTER_IPV6RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 2RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 3RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 6RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 9RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 10RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 11RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 12RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 13RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 14RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 16...RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 34RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 36RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 37RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 39...RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 47RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 49...RP/0/0/CPU0:R3(config-ipv6-acl)# deny any any dest-option-type 255RP/0/0/CPU0:R3(config-ipv6-acl)# permit ipv6 ............RP/0/0/CPU0:R3(config-ipv6-acl)# deny ipv6 any any logRP/0/0/CPU0:R3(config-ipv6-acl)# exitRP/0/0/CPU0:R3(config)# interface gigabitethernet 0/2/0/2RP/0/0/CPU0:R3(config-if)# ipv6 access-group FILTER_IPV6 ingressRP/0/0/CPU0:R3(config-if)# end

See Also

https://workbench.cisecurity.org/benchmarks/23599

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(11), CAT|II, CCI|CCI-002403, Rule-ID|SV-230160r856675_rule, STIG-ID|CISC-RT-000398, Vuln-ID|V-230160

Plugin: Cisco

Control ID: b98282807bece772ba5b66f630c245d91fbf700fafc4b614a63410d3824be802