The Cisco perimeter router must be configured to drop IPv6 packets containing a Hop-by-Hop header with invalid option type values.
An XCCDF Rule
Description
<VulnDiscussion>These options are intended to be for the Destination Options 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 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. </VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-230145r856667_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Drop IPv6 packets containing a Hop-by-Hop header as shown in the example below.
R1(config)#ipv6 access-list FILTER_IPV6
R1(config-ipv6-acl)#deny hbh any any dest-option-type 4 log
R1(config-ipv6-acl)#deny hbh any any dest-option-type 195 log
R1(config-ipv6-acl)#deny hbh any any dest-option-type home-address log