Detections
Analytics

1.38 CISC-RT-000395

Information

The Cisco perimeter router must be configured to drop IPv6 packets containing a Destination Option header with invalid option type values.

GROUP ID: V-230150
RULE ID: SV-230150r855848

These options are intended to be for the Hop-by-Hop header only. 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. Hence, this 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 IPv6 packets containing a Destination Option header with option type values of 0x05 (Router Alert) or 0xC2 (Jumbo Payload) as shown in the example below.

R1(config)#ipv6 access-list FILTER_IPV6
R1(config-ipv6-acl)#deny 60 any any dest-option-type 5 log
R1(config-ipv6-acl)#deny 60 any any dest-option-type 194 log
R1(config-ipv6-acl)#permit ...
...
...
...
R1(config-ipv6-acl)#deny ipv6 any any log
R1(config-ipv6-acl)#exit
R1(config)#int g1/0
R1(config-if)#ipv6 traffic-filter FILTER_IPV6
R1(config-if)#end

See Also

https://workbench.cisecurity.org/benchmarks/26261

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(11), CAT|II, CCI|CCI-002403, Rule-ID|SV-230150r855848_rule, STIG-ID|CISC-RT-000395, Vuln-ID|V-230150

Plugin: Cisco

Control ID: 1d8c24a2fedafc385f02386dc4fceae6e957839e2eb8c8b3d2445b482eb61021