The Bugzilla::Search::build_subselect function in Bugzilla 2.x and 3.x before 3.6.13 and 3.7.x and 4.0.x before 4.0.10 generates different error messages for invalid product queries depending on whether a product exists, which allows remote attackers to discover private product names by using debug mode for a query.
https://bugzilla.mozilla.org/show_bug.cgi?id=824399
http://www.mandriva.com/security/advisories?name=MDVSA-2013:066