CVE-2021-38503

The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR

CVE-2021-38504

When interacting with an HTML input element's file picker dialog with webkitdirectory set, a use-after-free could have resulted, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR

CVE-2021-43537

An incorrect type conversion of sizes from 64bit to 32bit integers allowed an attacker to corrupt memory leading to a potentially exploitable crash. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-38507

The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP addre...

CVE-2021-38508

By displaying a form validity message in the correct location at the same time as a permission prompt (such as for geolocation), the validity message could have obscured the prompt, resulting in the user potentially being tricked into granting the permission. This vulnerability affects Firefox <...

CVE-2021-43539

Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers. This could have led to a use-after-free causing a potentially exploitable crash. This vulnerability affects Thunderbird < 91.4.0, Firef...

CVE-2021-43536

Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-43546

It was possible to recreate previous cursor spoofing attacks against users with a zoomed native cursor. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-43538

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and F...

CVE-2021-43543

Documents loaded with the CSP sandbox directive could have escaped the sandbox's script restriction by embedding additional content. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-43541

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-38506

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR

CVE-2021-43542

Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-38509

Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR

CVE-2021-43545

Using the Location API in a loop could have caused severe application hangs and crashes. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox

CVE-2021-43535

A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.3, and Firefox ESR

CVE-2021-43534

Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. 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 F...

CVE-2021-43540

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox

CVE-2021-38510

The executable file warning was not presented when downloading .inetloc files, which, due to a flaw in Mac OS, can run commands on a user's computer.Note: This issue only affected Mac OS operating systems. Other operating systems are unaffected. . This vulnerability affects Firefox < 94, Thunder...

CVE-2021-38505

Microsoft introduced a new feature in Windows 10 known as Cloud Clipboard which, if enabled, will record data copied to the clipboard to the cloud, and make it available on other computers in certain scenarios. Applications that wish to prevent copied data from being recorded in Cloud History must ...

CVE-2021-43544

When receiving a URL through a SEND intent, Firefox would have searched for the text, but subsequent usages of the address bar might have caused the URL to load unintentionally, which could lead to XSS and spoofing attacks. This bug only affects Firefox for Android. Other operating systems are unaf...

CVE-2021-43532

The 'Copy Image Link' context menu action would copy the final image URL after redirects. By embedding an image that triggered authentication flows - in conjunction with a Content Security Policy that stopped a redirection chain in the middle - the final image URL could be one that contained an aut...

CVE-2021-43531

When a user loaded a Web Extensions context menu, the Web Extension could access the post-redirect URL of the element clicked. If the Web Extension lacked the WebRequest permission for the hosts involved in the redirect, this would be a same-origin-violation leaking data the Web Extension should ha...

CVE-2021-43530

A Universal XSS vulnerability was present in Firefox for Android resulting from improper sanitization when processing a URL scanned from a QR code. This bug only affects Firefox for Android. Other operating systems are unaffected. . This vulnerability affects Firefox

CVE-2021-43533

When parsing internationalized domain names, high bits of the characters in the URLs were sometimes stripped, resulting in inconsistencies that could lead to user confusion or attacks such as phishing. This vulnerability affects Firefox