The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape. *Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox ESR < 68.8 and Firefox < 76.
https://www.mozilla.org/security/advisories/mfsa2020-17/
https://www.mozilla.org/security/advisories/mfsa2020-16/
https://bugzilla.mozilla.org/show_bug.cgi?id=1618911
http://packetstormsecurity.com/files/157860/Firefox-Default-Content-Process-DACL-Sandbox-Escape.html