An issue has been found with the way that the vGW product enforces policies defined with network objects and/or SRX zones in rule matching criteria for IPv6 traffic. Traffic that is expected to be rejected based on the firewall policies could mistakenly be accepted. This could cause exposure to systems that are expected to have been protected by firewall policies on the vGW firewall. Note: This issue only applies to IPv6 and not IPv4. It also only affects IPv6 policies that use network objects and/or SRX zones in rule matching criteria. Juniper SIRT is not aware of any malicious exploitation of this vulnerability. This issue was found during proactive internal security audits.
Software updates for vGW have been released to resolve this issue. Releases containing the fix include 5.5r2. Version 5.0 is not affected by this issue. KB16765 [juniper.net] - "In which releases are vulnerabilities fixed?" describes which release vulnerabilities are fixed as per our End of Engineering and End of Life support policies.
How to obtain fixed software: Software release Service Packages are available at http://www.juniper.net/support/downloads/?p=vgw#sw
There are no known workarounds for this issue. The only way to correct this vulnerability is to upgrade to software that contains a fix.