Bugzilla 4.1.x and 4.2.x before 4.2.2 and 4.3.x before 4.3.2 uses bug-editor privileges instead of bugmail-recipient privileges during construction of HTML bugmail documents, which allows remote attackers to obtain sensitive description information by reading the tooltip portions of an HTML e-mail message.
https://bugzilla.mozilla.org/show_bug.cgi?id=777398