Mozilla: Sandbox escape via installation of malicious language pack

As part of a winning Pwn2Own entry, a researcher demonstrated a sandbox escape by installing a malicious language pack and then opening a browser feature that used the compromised translation. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.

A latent vulnerability exists in the Prio library where data may be read from uninitialized memory for some functions, leading to potential memory corruption. This vulnerability affects Firefox < 66.

Mozilla developers reported memory safety bugs present in Firefox 71. 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 < 72.

Mozilla: Memory safety bugs fixed in Firefox 72 and Firefox ESR 68.4

Mozilla developers reported memory safety bugs present in Firefox 71 and Firefox ESR 68.3. 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 < 68.4 and Firefox < 72.

When Python was installed on Windows, a python file being served with the MIME type of text/plain could be executed by Python instead of being opened as a text file when the Open option was selected upon download. *Note: this issue only occurs on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 72.

Mozilla: Type Confusion in XPCVariant.cpp

Due to a missing case handling object types, a type confusion vulnerability could occur, resulting in a crash. We presume that with enough effort that it could be exploited to run arbitrary code. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.

Mozilla: Memory corruption in parent process during new content process initialization on Windows

During the initialization of a new content process, a pointer offset can be manipulated leading to memory corruption and a potentially exploitable crash in the parent process. *Note: this issue only occurs on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.

Mozilla: Dragging and dropping a cross-origin resource, incorrectly loaded as an image, could result in information disclosure

If an image had not loaded correctly (such as when it is not actually an image), it could be dragged and dropped cross-domain, resulting in a cross-origin information leak. This vulnerability affects Firefox < 71.

Mozilla: Memory safety bugs fixed in Firefox 71

Mozilla developers reported memory safety bugs present in Firefox 70. 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 < 71.

Mozilla: Memory safety bugs fixed in Firefox 71 and Firefox ESR 68.3

Mozilla developers reported memory safety bugs present in Firefox 70 and Firefox ESR 68.2. 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 Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla: Use-after-free when retrieving a document in antitracking

Under certain conditions, when retrieving a document from a DocShell in the antitracking code, a race condition could cause a use-after-free condition and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla: Use-after-free when performing device orientation checks

Under certain conditions, when checking the Resist Fingerprinting preference during device orientation checks, a race condition could have caused a use-after-free and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla: Updater temporary files accessible to unprivileged processes

When running, the updater service wrote status and log files to an unrestricted location; potentially allowing an unprivileged process to locate and exploit a vulnerability in file handling in the updater service. *Note: This attack requires local system access and only affects Windows. Other operating systems are not affected.*. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla: Use-after-free in worker destruction

When using nested workers, a use-after-free could occur during worker destruction. This resulted in a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla: Buffer overflow in plain text serializer

The plain text serializer used a fixed-size array for the number of <ol> elements it could process; however it was possible to overflow the static-sized array leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Mozilla: Memory safety bugs fixed in Firefox 70 and Firefox ESR 68.2

Mozilla developers and community members reported memory safety bugs present in Firefox 69 and Firefox ESR 68.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Mozilla: Stack buffer overflow in WebRTC networking

A fixed-size stack buffer could overflow in nrappkit when doing WebRTC signaling. This resulted in a potentially exploitable crash in some instances. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Mozilla: Stack buffer overflow in HKDF output

An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Mozilla: Potentially exploitable crash due to 360 Total Security

Mozilla community member Philipp reported a memory safety bug present in Firefox 68 when 360 Total Security was installed. This bug showed evidence of memory corruption in the accessibility engine and we presume that with enough effort that it could be exploited to run arbitrary code. This vulnerability affects Firefox < 69, Thunderbird < 68.2, and Firefox ESR < 68.2.

Mozilla: Use-after-free when creating index updates in IndexedDB

When following the value's prototype chain, it was possible to retain a reference to a locale, delete it, and subsequently reference it. This resulted in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.