Security Vulnerabilities fixed in Firefox 85 — Mozilla

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.
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.
The browser could have been confused into transferring a pointer lock state into another tab, which could have lead to clickjacking attacks.
An ambiguous file picker design could have confused users who intended to select and upload a single file into uploading a whole directory. This was addressed by adding a new prompt.
Navigations through the Android-specific intent URL scheme could have been misused to escape iframe sandbox.Note: This issue only affected Firefox for Android. Other operating systems are unaffected.
The browser could have been confused into transferring a screen sharing state into another tab, which would leak unintended information.
An XSS bug in internal error pages could have led to various spoofing attacks, including other error pages and the address bar.Note: This issue only affected Firefox for Android. Other operating systems are unaffected.
Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash.
Further techniques that built on the slipstream research combined with a malicious webpage could have exposed both an internal network’s hosts as well as services running on the user’s local machine.
Incorrect use of the RowCountChanged method could have led to a user-after-poison and a potentially exploitable crash.
When sharing geolocation during an active WebRTC share, Firefox could have reset the webRTC sharing state in the user interface, leading to loss of control over the currently granted permission
Mozilla developers Andrew McCreight, Tyson Smith, Jesse Schwartzentruber, Jon Coppeard, Byron Campen, André Bargull, Steve Fink, Jason Kratzer, Christian Holler, Alexis Beingessner 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.
Mozilla developers Sebastian Hengst, Christian Holler, Tyson Smith reported memory safety bugs present in Firefox 84. 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.