A content process could have modified shared memory relating to crash reporting information, crash itself, and cause an out-of-bound write. This could have caused memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 73 and Firefox < ESR68.5.
https://www.mozilla.org/security/advisories/mfsa2020-06/
https://www.mozilla.org/security/advisories/mfsa2020-05/
https://usn.ubuntu.com/4278-2/