CVE-2012-1324
Race condition in the Zone-Based Firewall in Cisco IOS 15.1 and 15.2, when IPS policies are configured, allows remote attackers to cause a denial of service (device crash) by sending IPv6 packets, aka Bug ID CSCtk53534.
Date published : 2012-05-03
http://www.cisco.com/en/US/docs/ios/15_1/release/notes/151-3TCAVS.html