Mozilla developers backported selected changes in the Skia library. These changes correct memory corruption issues including invalid buffer reads and writes during graphic operations. This vulnerability affects Thunderbird ESR < 52.8, Thunderbird < 52.8, and Firefox ESR < 52.8.

If a text string that happens to be a filename in the operating system's native format is dragged and dropped onto the addressbar the specified local file will be opened. This is contrary to policy and is what would happen if the string were the equivalent "file:" URL. This vulnerability affects Firefox < 60.

If a URL using the "file:" protocol is dragged and dropped onto an open tab that is running in a different child process the tab will open a local file corresponding to the dropped URL, contrary to policy. One way to make the target tab open more reliably in a separate process is to open it with the "noopener" keyword. This vulnerability affects Firefox < 60.

A use-after-free vulnerability can occur during WebGL operations. While this results in a potentially exploitable crash, the vulnerability is limited because the memory is freed and reused in a brief window of time during the freeing of the same callstack. This vulnerability affects Firefox < 60.

A buffer overflow was found during UTF8 to Unicode string conversion within JavaScript with extremely large amounts of data. This vulnerability requires the use of a malicious or vulnerable legacy extension in order to occur. This vulnerability affects Thunderbird ESR < 52.8, Thunderbird < 52.8, and Firefox ESR < 52.8.

A vulnerability exists in XSLT during number formatting where a negative buffer size may be allocated in some instances, leading to a buffer overflow and crash if it occurs. This vulnerability affects Firefox < 60.

The JSON Viewer displays clickable hyperlinks for strings that are parseable as URLs, including "javascript:" links. If a JSON file contains malicious JavaScript script embedded as "javascript:" links, users may be tricked into clicking and running this code in the context of the JSON Viewer. This can allow for the theft of cookies and authorization tokens which are accessible to that context. This vulnerability affects Firefox < 60.

A mechanism to bypass Content Security Policy (CSP) protections on sites that have a "script-src" policy of "'strict-dynamic'". If a target website contains an HTML injection flaw an attacker could inject a reference to a copy of the "require.js" library that is part of Firefox's Developer Tools, and then use a known technique using that library to bypass the CSP restrictions on executing injected scripts. This vulnerability affects Firefox < 60.

The filename appearing in the "Downloads" panel improperly renders some Unicode characters, allowing for the file name to be spoofed. This can be used to obscure the file extension of potentially executable files from user view in the panel. Note: the dialog to open the file will show the full, correct filename and whether it is executable or not. This vulnerability affects Firefox < 60.

The Live Bookmarks page and the PDF viewer can run injected script content if a user pastes script from the clipboard into them while viewing RSS feeds or PDF files. This could allow a malicious site to socially engineer a user to copy and paste malicious script content that could then run with the context of either page but does not allow for privilege escalation. This vulnerability affects Firefox < 60.

It is possible to spoof the filename of an attachment and display an arbitrary attachment name. This could lead to a user opening a remote attachment which is a different file type than expected. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

If manipulated hyperlinked text with "chrome:" URL contained in it is dragged and dropped on the "home" icon, the home page can be reset to include a normally-unlinkable chrome page as one of the home page tabs. This vulnerability affects Firefox < 60.

Sites can bypass security checks on permissions to install lightweight themes by manipulating the "baseURI" property of the theme element. This could allow a malicious site to install a theme without user interaction which could contain offensive or embarrassing images. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

The web console and JavaScript debugger do not sanitize all output that can be hyperlinked. Both will display "chrome:" links as active, clickable hyperlinks in their output. Web sites should not be able to directly link to internal chrome pages. Additionally, the JavaScript debugger will display "javascript:" links, which users could be tricked into clicking by malicious sites. This vulnerability affects Firefox < 60.

WebExtensions can use request redirection and a "filterReponseData" filter to bypass host permission settings to redirect network traffic and access content from a host for which they do not have explicit user permission. This vulnerability affects Firefox < 60.

Content Security Policy (CSP) is not applied correctly to all parts of multipart content sent with the "multipart/x-mixed-replace" MIME type. This could allow for script to run where CSP should block it, allowing for cross-site scripting (XSS) and other attacks. This vulnerability affects Firefox < 60.

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.

Plaintext of decrypted emails can leak through the src attribute of remote images, or links. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

Crafted message headers can cause a Thunderbird process to hang on receiving the message. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

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.