Mozilla: A popup window could be resized in a way to overlay the address bar with web content

A malicious website that could create a popup could have resized the popup to overlay the address bar with its own content, resulting in potential user confusion or spoofing attacks. <br>*This bug only affects Thunderbird for Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

Mozilla: Microsoft protocols can be attacked if a user accepts a prompt

The <code>ms-msdt</code>, <code>search</code>, and <code>search-ms</code> protocols deliver content to Microsoft applications, bypassing the browser, when a user accepts a prompt. These applications have had known vulnerabilities, exploited in the wild (although we know of none exploited through Thunderbird), so in this release Thunderbird has blocked these protocols from prompting the user to open them.<br>*This bug only affects Thunderbird on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

The MediaError message property should be consistent to avoid leaking information about cross-origin resources; however for a same-site cross-origin resource, the message could have leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 102.

ASN.1 parsing of an indefinite SEQUENCE inside an indefinite GROUP could have resulted in the parser accepting malformed ASN.1. This vulnerability affects Firefox < 102.

When downloading an update for an addon, the downloaded addon update's version was not verified to match the version selected from the manifest. If the manifest had been tampered with on the server, an attacker could trick the browser into downgrading the addon to a prior version. This vulnerability affects Firefox < 102.

Mozilla: Use-after-free in nsSHistory

Session history navigations may have led to a use-after-free and potentially exploitable crash. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

When a TLS Certificate error occurs on a domain protected by the HSTS header, the browser should not allow the user to bypass the certificate error. On Firefox for Android, the user was presented with the option to bypass the error; this could only have been done by the user explicitly. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102.

Mozilla: CSP sandbox header without `allow-scripts` can be bypassed via retargeted javascript: URI

An iframe that was not permitted to run scripts could do so if the user clicked on a <code>javascript:</code> link. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

Mozilla developers Gabriele Svelto, Timothy Nikkel, Randell Jesup, Jon Coppeard, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 100. 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 < 101.

Mozilla: Memory safety bugs fixed in Firefox 101 and Firefox ESR 91.10

Mozilla developers Andrew McCreight, Nicolas B. Pierron, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 100 and Firefox ESR 91.9. 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 < 91.10, Firefox < 101, and Firefox ESR < 91.10.

If array shift operations are not used, the Garbage Collector may have become confused about valid objects. This vulnerability affects Firefox < 101.

Mozilla: CSP bypass enabling stylesheet injection

An attacker could have injected CSS into stylesheets accessible via internal URIs, such as resource:, and in doing so bypass a page's Content Security Policy. This vulnerability affects Firefox ESR < 91.11, Thunderbird < 102, Thunderbird < 91.11, and Firefox < 101.

Firefox's HTML parser did not correctly interpret HTML comment tags, resulting in an incongruity with other browsers. This could have been used to escape HTML comments on pages that put user-controlled data in them. This vulnerability affects Firefox < 101.

Mozilla: Querying a WebAuthn token with a large number of allowCredential entries may have leaked cross-origin information

An attacker could have exploited a timing attack by sending a large number of allowCredential entries and detecting the difference between invalid key handles and cross-origin key handles. This could have led to cross-origin account linking in violation of WebAuthn goals. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

Mozilla: Uninitialized variable leads to invalid memory read

A crafted CMS message could have been processed incorrectly, leading to an invalid memory read, and potentially further memory corruption. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

Mozilla: Memory safety bugs fixed in Firefox 104, Firefox ESR 102.2, and Firefox ESR 91.13

Members the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 103, Firefox ESR 102.1, and Firefox ESR 91.12. 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 < 102.2, Thunderbird < 91.13, Firefox ESR < 91.13, Firefox ESR < 102.2, and Firefox < 104.

Mozilla: Memory safety bugs fixed in Firefox 104 and Firefox ESR 102.2

Mozilla developer Nika Layzell and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 103 and Firefox ESR 102.1. 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 < 102.2, Thunderbird < 102.2, and Firefox < 104.

Mozilla: Data race and potential use-after-free in PK11_ChangePW

A data race could occur in the <code>PK11_ChangePW</code> function, potentially leading to a use-after-free vulnerability. In Firefox, this lock protected the data when a user changed their master password. This vulnerability affects Firefox ESR < 102.2 and Thunderbird < 102.2.

An attacker could have written a value to the first element in a zero-length JavaScript array. Although the array was zero-length, the value was not written to an invalid memory address. This vulnerability affects Firefox < 104.

When using the Performance API, an attacker was able to notice subtle differences between PerformanceEntries and thus learn whether the target URL had been subject to a redirect. This vulnerability affects Firefox < 103.