Information
A third-party cookie is a cookie sent by a domain that differs from the domain in the browser's address bar.
Third party cookies are often used for tracking user browsing behaviors, which has privacy implications. However, preventing third-party cookies does not completely mitigate privacy concerns as several other active tracking mechanisms exist[1].
Solution
Perform the following procedure:
* Open the mozilla.cfg file in the installation directory with a text editor
* Add the following lines to mozilla.cfg:
lockPref("network.cookie.cookieBehavior", 1);