#firefox

A Time-of-Check Time-of-Use bug existed in the Maintenance (Updater) Service that could be abused to grant Users write access to an arbitrary directory. This could have been used to escalate to SYSTEM access.<br>*This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.

If a user was convinced to drag and drop an image to their desktop or other folder, the resulting object could have been changed into an executable script which would have run arbitrary code after the user clicked on it. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.

When navigating from inside an iframe while requesting fullscreen access, an attacker-controlled tab could have made the browser unable to leave fullscreen mode. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.

Securitypolicyviolation events could have leaked cross-origin information for frame-ancestors violations. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.

If Firefox was installed to a world-writable directory, a local privilege escalation could occur when Firefox searched the current directory for system libraries. However the install directory is not world-writable by default.<br>*This bug only affects Firefox for Windows in a non-default installation. Other operating systems are unaffected.*. This vulnerability affects Firefox < 96.

Malicious websites could have confused Firefox into showing the wrong origin when asking to launch a program and handling an external URL protocol. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.

Mozilla developers Christian Holler and Jason Kratzer reported memory safety bugs present in Firefox 95. 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 < 96.

By using XSL Transforms, a malicious webserver could have served a user an XSL document that would continue to execute JavaScript (within the bounds of the same-origin policy) even after the tab was closed. This vulnerability affects Firefox < 97.

Mozilla developers Kershaw Chang, Ryan VanderMeulen, and Randell Jesup reported memory safety bugs present in Firefox 97. 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 < 98.

If a document created a sandboxed iframe without <code>allow-scripts</code>, and subsequently appended an element to the iframe's document that e.g. had a JavaScript event handler - the event handler would have run despite the iframe's sandbox. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.