Template.pm in Bugzilla 2.x, 3.x, and 4.x before 4.2.16, 4.3.x and 4.4.x before 4.4.11, and 4.5.x and 5.0.x before 5.0.2 does not properly construct CSV files, which allows remote attackers to obtain sensitive information by leveraging a web browser that interprets CSV data as JavaScript code.
https://www.bugzilla.org/security/4.2.15/
http://www.securitytracker.com/id/1034556
http://www.securityfocus.com/bid/79662
http://seclists.org/bugtraq/2015/Dec/131
http://packetstormsecurity.com/files/135048/Bugzilla-Cross-Site-Scripting-Information-Leak.html