Mozilla is adding a new protection feature to its Firefox browser that is designed to impede redirect tracking. In other words, Firefox 79 has added protection against redirect tracking.
Redirect tracking is a new user tracking technique utilized by online advertisers. The inclusion of this protection feature to Firefox is a logical step since Mozilla has been building up its anti-fingerprinting protections for years. These protections include an anti-tracking policy, ETP (enhanced tracking protection), cross-site and third-party tracking cookies.
More about Redirect Tracking
“Redirect tracking is an abuse of cross-site navigation in which a tracker momentarily redirects a user to their website for the purpose of using first-party storage to track that user across websites,” Mozilla says in the official document describing the new protection feature.
But how exactly does it work? Redirect trackers force users to make a subtle and unnoticable stopover to particular websites. This means that rather than navigating directly from the review website to the retailer website, the user will end up on the redirect tracker first. In other words, the tracker is loaded as a first party, Mozilla explains, and it associates tracking data with the identifiers stored in first-party cookies. The final step is forwarding the user to the retailer.
Redirect Tracking Protection: How Does It Work
Firefox periodically clears cookies and site data from trackers, as a means to protect against redirect tracking. Firefox 79 is designed to clear out any cookies and site data kept by known trackers. This procedure is done every 24 hours.
As explained by Steven Englehardt, privacy engineer at Mozilla,”when you first visit a redirect tracker it can store a unique identifier in its cookies.”
Any redirects to that tracker during the 24 hour window will be able to associate tracking data with that same identifying cookie. However, once ETP 2.0’s cookie clearing runs, the identifying cookies will be deleted from Firefox and you’ll look like a fresh user the next time you visit the tracker, the expert adds.
It should be noted that cookies from non-tracking websites will not be cleared, such as cookies that allow users to remain logged into various accounts.
A 45-day exception for any trackers that a user has interacted with directly is also procided. This way users can continue to have good experiences on their websites, as regularly visited websites will continue to function as expected, with redirects trackers having their storage regularly cleared.