Mozilla firefox us vulnerable to developer reported memory safety bugs present in Firefox 83 and Firefox ESR 78.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
bugzilla.mozilla.org/buglist.cgi?bug_id=1664831%2C1673589
git.launchpad.net/ubuntu-cve-tracker/tree/active/CVE-2020-35113
www.mozilla.org/en-US/security/advisories/mfsa2020-55/#CVE-2020-35113
www.mozilla.org/security/advisories/mfsa2020-54/
www.mozilla.org/security/advisories/mfsa2020-55/
www.mozilla.org/security/advisories/mfsa2020-56/