The Juniper perimeter router must be configured to drop IPv6 packets containing the NSAP address option within Destination Option header.
An XCCDF Rule
Description
<VulnDiscussion>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. This option type from RFC 1888 (OSI NSAPs and IPv6) has been deprecated by RFC 4048.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-233298r604135_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Step 1: Configure a filter to block packets with a Destination Option header as shown in the example.
user@R1# edit firewall family inet6
user@R1# edit filter IPV6-INGRESS-FILTER
user@R1# set term DEST_ OPT_HEADER from next-header dstops
user@R1# set term DEST_ OPT_HEADER then discard syslog