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IPv6 traffic tunneled through IPv4 is being bypassed by a services gateway



Article ID: JSA10480 SECURITY_ADVISORIES Last Updated: 09 May 2013Version: 4.0
Legacy Advisory Id:
Product Affected:
This issue can affect any SRX Series services gateway or J Series services router configured to tunnel IPv6 traffic over IPv4.

When using a branch or data center SRX Series Services Gateway or J Series Services Router to perform 6to4 (IPv6 in IPv4) tunneling, policies applied to the directly encapsulated IPv6 datagrams within the IPv4 tunneled traffic (IP protocol number 41) are bypassed. Two problems were uncovered during the investigation:
  • IPv6 traffic within IPv6-over-IPv4 and IPv6-in-IPv4 tunnels bypass policy on the device.
  • For IP-IP tunnels, only an IPv4 over IPv4 tunnel session (IP protocol number 4) is created. IPv6 packets over IPv4 tunnels can't match the tunnel session and policy cannot be applied.
This issue only affects policy processing and not encapsulation or forwarding.

IPv6 over IPv4 packets will now be forwarded through the device. Customers can configure policies to enable/disable forwarding this kind of traffic.

All JUNOS software releases built on or after 2011-01-31 have fixed this specific issue. Releases containing the fix specifically include: 9.3S19.1, 10.0S13, 10.2R3, 10.3R3, 10.4R1, and all subsequent releases (i.e. all releases built after 10.4R1).

This issue is being tracked as PR 539581. While this PR may not be viewable by customers, it can be used as a reference when discussing the issue with JTAC.

KB16765 - "In which releases are vulnerabilities fixed?" describes which release vulnerabilities are fixed as per our End of Engineering and End of Life support policies.


No known workaround exists for this issue.

How to obtain fixed software:
Security vulnerabilities in Junos are fixed in the next available Maintenance Release of each supported Junos version. In some cases, a Maintenance Release is not planned to be available in an appropriate time-frame. For these cases, Service Releases are made available in order to be more timely. Security Advisory and Security Notices will indicate which Maintenance and Service Releases contain fixes for the issues described. Upon request to JTAC, customers will be provided download instructions for a Service Release. Although Juniper does not provide formal Release Note documentation for a Service Release, a list of "PRs fixed" can be provided on request.
CVSS Score:
5.0 (AV:N/AC:L/Au:N/C:P/I:N/A:N)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

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