If a Thunderbird user replied to a crafted HTML email containing a <code>meta</code> tag, with the <code>meta</code> tag having the <code>http-equiv="refresh"</code> attribute, and the content attribute specifying an URL, then Thunderbird started a network request to that URL, regardless of the configuration to block remote content. In combination with certain other HTML elements and attributes in the email, it was possible to execute JavaScript code included in the message in the context of the message compose document. The JavaScript code was able to perform actions including, but probably not limited to, read and modify the contents of the
When receiving an HTML email that contained an <code>iframe</code> element, which used a <code>srcdoc</code> attribute to define the inner HTML document, remote objects specified in the nested document, for example images or videos, were not blocked. Rather, the network was accessed, the objects were loaded and displayed. This vulnerability affects Thunderbird < 102.2.1 and Thunderbird < 91.13.1.
Mozilla developers Andrew McCreight, Gabriele Svelto, Tom Ritter and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 99 and Firefox ESR 91.8. 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 Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
Firefox behaved slightly differently for already known resources when loading CSS resources involving CSS variables. This could have been used to probe the browser history. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
When reusing existing popups Firefox would have allowed them to cover the fullscreen notification UI, which could have enabled browser spoofing attacks. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
The parent process would not properly check whether the Speech Synthesis feature is enabled, when receiving instructions from a child process. This vulnerability affects Thunderbird < 91.9.
Requests initiated through reader mode did not properly omit cookies with a SameSite attribute. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
An improper implementation of the new iframe sandbox keyword <code>allow-top-navigation-by-user-activation</code> could lead to script execution without <code>allow-scripts</code> being present. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
Documents in deeply-nested cross-origin browsing contexts could have obtained permissions granted to the top-level origin, bypassing the existing prompt and wrongfully inheriting the top-level permissions. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
Mozilla developers and community members Nika Layzell, Andrew McCreight, Gabriele Svelto, and the Mozilla Fuzzing Team reported memory safety bugs present in Thunderbird 91.7. 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 Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.
Due to a layout change, iframe contents could have been rendered outside of its border. This could have led to user confusion or spoofing attacks. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.
When generating the assembly code for <code>MLoadTypedArrayElementHole</code>, an incorrect AliasSet was used. In conjunction with another vulnerability this could have been used for an out of bounds memory read. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.
By using a link with <code>rel="localization"</code> a use-after-free could have been triggered by destroying an object during JavaScript execution and then referencing the object through a freed pointer, leading to a potential exploitable crash. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.
If a compromised content process sent an unexpected number of WebAuthN Extensions in a Register command to the parent process, an out of bounds write would have occurred leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.
An unexpected message in the WebGPU IPC framework could lead to a use-after-free and exploitable sandbox escape. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.
Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.
When installing an add-on, Firefox verified the signature before prompting the user; but while the user was confirming the prompt, the underlying add-on file could have been modified and Firefox would not have noticed. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.
Previously Firefox for macOS and Linux would download temporary files to a user-specific directory in <code>/tmp</code>, but this behavior was changed to download them to <code>/tmp</code> where they could be affected by other local users. This behavior was reverted to the original, user-specific directory. <br>*This bug only affects Firefox for macOS and Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 91.7 and Thunderbird < 91.7.
If an attacker could control the contents of an iframe sandboxed with <code>allow-popups</code> but not <code>allow-scripts</code>, they were able to craft a link that, when clicked, would lead to JavaScript execution in violation of the sandbox. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.
When resizing a popup after requesting fullscreen access, the popup would not display the fullscreen notification. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.