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.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.