Bugzilla 3.3.1 through 3.4.4, 3.5.1, and 3.5.2 does not allow group restrictions to be preserved throughout the process of moving a bug to a different product category, which allows remote attackers to obtain sensitive information via a request for a bug in opportunistic circumstances.
https://exchange.xforce.ibmcloud.com/vulnerabilities/56004
https://bugzilla.mozilla.org/show_bug.cgi?id=532493
http://www.vupen.com/english/advisories/2010/0261
http://www.securityfocus.com/bid/38026
http://www.securityfocus.com/archive/1/509282/100/0/threaded