The Firefox team announced a new security measure to be implemented in Firefox 88. The popular web browser introduces new protection against privacy leaks on the web. With the new limitations, trackers will not be able to abuse the window.name property to track users across websites.
Windows.name data leaking
The Mozilla team stated that data stored in window.name has been allowed by standard browser rules to leak between websites. It enables trackers to identify users or snoop on their browsing history. The window.name property is available to any visited website and stores any data the website to place there. According to the announcement, data stored in the window.name property was allowed by all major browsers to persist across page visits in the same tab.
Firefox will now clear the window.name property to prevent potential leakages. Firefox will also attempt to identify likely non-harmful usage of window.name and avoid clearing the property in such cases. To prevent leakages, Firefox restores the window.name property to its previous value for that website when the user navigates back to a previous website. Clearing and restoring window.name data effectively confine that data to the website where it was created is similar to how Firefox’s Total Cookie Protection confines cookies to the website where they were created.