A mechanism was discovered that removes some bounds checking for string, array, or typed array accesses if Spectre mitigations have been disabled. This vulnerability could allow an attacker to create an arbitrary value in compiled JavaScript, for which the range analysis will infer a fully controlled, incorrect range in circumstances where users have explicitly disabled Spectre mitigations. *Note: Spectre mitigations are currently enabled for all users by default settings.*. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

The type inference system allows the compilation of functions that can cause type confusions between arbitrary objects when compiled through the IonMonkey just-in-time (JIT) compiler and when the constructor function is entered through on-stack replacement (OSR). This allows for possible arbitrary reading and writing of objects during an exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

A use-after-free vulnerability can occur when a raw pointer to a DOM element on a page is obtained using JavaScript and the element is then removed while still in use. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

Mozilla developers and community members reported memory safety bugs present in Firefox 65. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 66.

Mozilla developers and community members reported memory safety bugs present in Firefox 65, Firefox ESR 60.5, and Thunderbird 60.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

The about:crashcontent and about:crashparent pages can be triggered by web content. These pages are used to crash the loaded page or the browser for test purposes. This issue allows for a non-persistent denial of service (DOS) attack by a malicious site which links to these pages. This vulnerability affects Firefox < 64.

A potential vulnerability leading to an integer overflow can occur during buffer size calculations for images when a raw value is used instead of the checked value. This leads to a possible out-of-bounds write. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

Limitations on the URIs allowed to WebExtensions by the browser.windows.create API can be bypassed when a pipe in the URL field is used within the extension to load multiple pages as a single argument. This could allow a malicious WebExtension to open privileged about: or file: locations. This vulnerability affects Firefox < 64.

When the RSS Feed preview about:feeds page is framed within another page, it can be used in concert with scripted content for a clickjacking attack that confuses users into downloading and executing an executable file from a temporary directory. *Note: This issue only affects Windows operating systems. Other operating systems are not affected.*. This vulnerability affects Firefox < 64.

WebExtension content scripts can be loaded into about: pages in some circumstances, in violation of the permissions granted to extensions. This could allow an extension to interfere with the loading and usage of these pages and use capabilities that were intended to be restricted from extensions. This vulnerability affects Firefox < 64.

A same-origin policy violation allowing the theft of cross-origin URL entries when using the Javascript location property to cause a redirection to another site using performance.getEntries(). This is a same-origin policy violation and could allow for data theft. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

A buffer overflow can occur in the Skia library during buffer offset calculations with hardware accelerated canvas 2D actions due to the use of 32-bit calculations instead of 64-bit. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

A use-after-free vulnerability can occur after deleting a selection element due to a weak reference to the select element in the options collection. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

A buffer overflow occurs when drawing and validating elements with the ANGLE graphics library, used for WebGL content, when working with the VertexBuffer11 module. This results in a potentially exploitable crash. This vulnerability affects Firefox < 64.

Mozilla developers and community members reported memory safety bugs present in Firefox 63. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 64.

Mozilla developers and community members reported memory safety bugs present in Firefox 63 and Firefox ESR 60.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

When proxy auto-detection is enabled, if a web server serves a Proxy Auto-Configuration (PAC) file or if a PAC file is loaded locally, this PAC file can specify that requests to the localhost are to be sent through the proxy to another server. This behavior is disallowed by default when a proxy is manually configured, but when enabled could allow for attacks on services and tools that bind to the localhost for networked behavior if they are accessed through browsing. This vulnerability affects Firefox < 65.

An earlier fix for an Inter-process Communication (IPC) vulnerability, CVE-2011-3079, added authentication to communication between IPC endpoints and server parents during IPC process creation. This authentication is insufficient for channels created after the IPC process is started, leading to the authentication not being correctly applied to later channels. This could allow for a sandbox escape through IPC channels due to lack of message validation in the listener process. This vulnerability affects Thunderbird < 60.5, Firefox ESR < 60.5, and Firefox < 65.

A crash and out-of-bounds read can occur when the buffer of a texture client is freed while it is still in use during graphic operations. This results is a potentially exploitable crash and the possibility of reading from the memory of the freed buffers. This vulnerability affects Firefox < 65.