When a worker is shutdown, it was possible to cause script to run late in the lifecycle, at a point after where it should not be possible. This vulnerability affects Firefox < 96, Thunderbird < 91.6, and Firefox ESR < 91.6.
Mozilla developers Paul Adenot and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 96 and Firefox ESR 91.5. 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. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.
An attacker could have caused a use-after-free by forcing a text reflow in an SVG object leading to a potentially exploitable crash. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.
When clicking on a tel: link, USSD codes, specified after a <code>\*</code> character, would be included in the phone number. On certain phones, or on certain carriers, if the number was dialed this could perform actions on a user's account, similar to a cross-site request forgery attack.<br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 97.
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.
When importing resources using Web Workers, error messages would distinguish the difference between <code>application/javascript</code> responses and non-script responses. This could have been abused to learn information cross-origin. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.
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.
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.
Remote Agent, used in WebDriver, did not validate the Host or Origin headers. This could have allowed websites to connect back locally to the user's browser to control it. <br>*This bug only affected Firefox when WebDriver was enabled, which is not the default configuration.*. This vulnerability affects Firefox < 97.
Mozilla developers Calixte Denizet, Kershaw Chang, Christian Holler, Jason Kratzer, Gabriele Svelto, Tyson Smith, Simon Giesecke, and Steve Fink reported memory safety bugs present in Firefox 95 and Firefox ESR 91.4. 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 ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.