If a malicious attacker has used another vulnerability to gain full control over a content process, they may be able to replace the alternate data resources stored in the JavaScript Start-up Bytecode Cache (JSBC) for other JavaScript code. If the parent process then runs this replaced code, the executed script would be run with the parent process' privileges, escaping the sandbox on content processes. This vulnerability affects Firefox < 60.

WebRTC can use a "WrappedI420Buffer" pixel buffer but the owning image object can be freed while it is still in use. This can result in the WebRTC encoder using uninitialized memory, leading to a potentially exploitable crash. This vulnerability affects Firefox < 60.

An integer overflow can occur in the Skia library due to 32-bit integer use in an array without integer overflow checks, resulting in possible out-of-bounds writes. This could lead to a potentially exploitable crash triggerable by web content. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

The PDF viewer does not sufficiently sanitize PostScript calculator functions, allowing malicious JavaScript to be injected through a crafted PDF file. This JavaScript can then be run with the permissions of the PDF viewer by its worker. This vulnerability affects Firefox ESR < 52.8 and Firefox < 60.

Same-origin protections for the PDF viewer can be bypassed, allowing a malicious site to intercept messages meant for the viewer. This could allow the site to retrieve PDF files restricted to viewing by an authenticated user on a third-party website. This vulnerability affects Firefox ESR < 52.8 and Firefox < 60.

A vulnerability can occur when capturing a media stream when the media source type is changed as the capture is occuring. This can result in stream data being cast to the wrong type causing a potentially exploitable crash.

A use-after-free vulnerability can occur while adjusting layout during SVG animations with text paths. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

A use-after-free vulnerability can occur while enumerating attributes during SVG animations with clip paths. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

If websocket data is sent with mixed text and binary in a single message, the binary data can be corrupted. This can result in an out-of-bounds read with the read memory sent to the originating server in response. This vulnerability affects Firefox < 60.

WebExtensions with the appropriate permissions can attach content scripts to Mozilla sites such as accounts.firefox.com and listen to network traffic to the site through the "webRequest" API. For example, this allows for the interception of username and an encrypted password during login to Firefox Accounts. This issue does not expose synchronization traffic directly and is limited to the process of user login to the website and the data displayed to the user once logged in. This vulnerability affects Firefox < 60.