Mozilla: Memory safety bugs fixed in Firefox 79 and Firefox ESR 68.11

Mozilla developers and community members reported memory safety bugs present in Firefox 78 and Firefox ESR 78.0. 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 < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.

Mozilla: Overriding file type when saving to disk

The code for downloading files did not properly take care of special characters, which led to an attacker being able to cut off the file ending at an earlier position, leading to a different file type being downloaded than shown in the dialog. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Mozilla: DLL hijacking due to incorrect loading path

Firefox could be made to load attacker-supplied DLL files from the installation directory. This required an attacker that is already capable of placing files in the installation directory. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Mozilla: Type confusion for special arguments in IonMonkey

JIT optimizations involving the Javascript arguments object could confuse later optimizations. This risk was already mitigated by various precautions in the code, resulting in this bug rated at only moderate severity. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Mozilla: Extension APIs could be used to bypass Same-Origin Policy

A redirected HTTP request which is observed or modified through a web extension could bypass existing CORS checks, leading to potential disclosure of cross-origin information. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Mozilla: Custom cursor can overlay user interface

When in an endless loop, a website specifying a custom cursor using CSS could make it look like the user is interacting with the user interface, when they are not. This could lead to a perceived broken state, especially when interactions with existing browser dialogs and warnings do not work. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Mozilla: Bypassing iframe sandbox when allowing popups

An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links. This could have led to security issues for websites relying on sandbox configurations that allowed popups and hosted arbitrary content. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Mozilla: Potential leak of redirect targets when loading scripts in a worker

By observing the stack trace for JavaScript errors in web workers, it was possible to leak the result of a cross-origin redirect. This applied only to content that can be parsed as script. This vulnerability affects Firefox < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.

A unicode RTL order character in the downloaded file name can be used to change the file's name during the download UI flow to change the file extension. This vulnerability affects Firefox for iOS < 28.

Mozilla: Overwriting local files through malicious file picker application

Given an installed malicious file picker application, an attacker was able to overwrite local files and thus overwrite Firefox settings (but not access the previous profile). *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.11.

Mozilla: Exfiltrating local files through malicious file picker application

Given an installed malicious file picker application, an attacker was able to steal and upload local files of their choosing, regardless of the actually files picked. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.11.

Mozilla: X-Frame-Options bypass using object or embed tags

Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.

A Content Provider in Firefox for Android allowed local files accessible by the browser to be read by a remote webpage, leading to sensitive data disclosure, including cookies for other origins. This vulnerability affects Firefox for < Android.

Mozilla: Automatic account setup leaks Microsoft Exchange login credentials

If an attacker intercepts Thunderbird's initial attempt to perform automatic account setup using the Microsoft Exchange autodiscovery mechanism, and the attacker sends a crafted response, then Thunderbird sends username and password over https to a server controlled by the attacker. This vulnerability affects Thunderbird < 68.10.0.

libjpeg-turbo: heap-based buffer over-read in get_rgb_row() in rdppm.c

libjpeg-turbo 2.0.4, and mozjpeg 4.0.0, has a heap-based buffer over-read in get_rgb_row() in rdppm.c via a malformed PPM input file.

Mozilla: Memory safety bugs fixed in Thunderbird 78

Mozilla developers and community members reported memory safety bugs present in Firefox 77. 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 < 78.

Mozilla: Out of bound read in Date.parse()

Due to confusion processing a hyphen character in Date.parse(), a one-byte out of bounds read could have occurred, leading to potential information disclosure. This vulnerability affects Firefox < 78.

Mozilla: WebRTC permission prompt could have been bypassed by a compromised content process

When constructing a permission prompt for WebRTC, a URI was supplied from the content process. This URI was untrusted, and could have been the URI of an origin that was previously granted permission; bypassing the prompt. This vulnerability affects Firefox < 78.

Mozilla: DLL Hijacking due to searching %PATH% for a library

When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. *Note: This issue only affects the Windows operating system; other operating systems are unaffected.* This vulnerability affects Firefox < 78.

Mozilla: Integer overflow in nsJPEGEncoder::emptyOutputBuffer

In non-standard configurations, a JPEG image created by JavaScript could have caused an internal variable to overflow, resulting in an out of bounds write, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 78.