Known Vulnerabilities
CVE-2021-23964
Mozilla developers reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6. 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. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.
CVE-2021-23953
If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.
CVE-2021-23954
Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.
CVE-2021-23960
Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.