Mozilla has billed the move as a way to boost the stability of its browser. The new feature will bar access to Firefox s components directory, where most of its own code is stored. Mozilla has patched a number of critical vulnerabilities in Firefox 44 and Firefox Extended Release 38.6, which were released this week. For the first time it will pay for some bugs whose severity is rated moderate, Mozilla announced that it has increased rewards for vulnerabilities submitted to its bug bounty program.
Source: https://threatpost.com/access-closed-component-directory-firefox-36-111809/73124/