One of our developers discovered that, starting on about May 4th, 2014, for a period of around 3 months, during the migration of our testing server for test builds of the Bugzilla software, database dump files containing email addresses and encrypted passwords of roughly 97,000 users of the test build were posted on a publicly accessible server. As soon as we became aware, the database dump files were removed from the server immediately, and we’ve modified the testing process to not require database dumps.
Generally, developers who use our test builds have told us they understand that these builds are insecure and may break, so they do not use passwords they would reuse elsewhere. However, because it is possible that some users could have reused their passwords on other websites or authentication systems, we’ve sent notices to the users who were affected by this disclosure and recommended that they change any similar passwords they may be using. It’s important to note that, unless users reused the password they used on landfill.bugzilla.org, this does not affect bugzilla.mozilla.org email addresses or passwords.
The Bugzilla Update Blog: http://bugzillaupdate.wordpress.com/2014/08/27/landfill-bugzilla-org-disclosure/