Mozilla has blocked and removed 23 Firefox extensions that tracked users, including an extension the browser developer itself recently promoted. This appears from a mention by Mozilla on its own Firefox block list and Bugzilla. Mozilla regularly promotes Firefox extensions.
Last week, Mozilla advertised add-ons to protect privacy in a blog post. One of the recommended add-ons was “Web Security”, that claimed to protect users against malicious websites. The add-in was installed by about 220,000 users. A couple of users discovered that the extension sends data to a server when the users visited websites. Mozilla therefore decided to remove the extension from the blog post and to analyze the behavior of the extension.
Now Mozilla states it has removed and blocked Web Security and 22 other extensions because they unnecessarily sent user data to servers and in some cases also in an insecure way. Besides that, the behavior was not clearly explained to users. Also, the extensions made it possible to remotely execute code, which is a security issue.
Mozilla also discovered that several extensions with different features and authors made use of the same source code. Further investigation made clear that they all came from the same author or group. Therefore, Mozilla decided to remove 23 extensions from add-ons.mozilla.org and block them in the browser of users who have them installed.
Besides Web Security, also Browser Security, Browser Privacy and Browser Safety are blocked and removed, as well as YouTube MP3 Converter, Dirty Little Helpers and Video Downloader.