Add-on updates failed to verify that the add-on ID inside the signed package matched the ID of the add-on being updated. An attacker who could perform a man-in-the-middle attack on the user's connection to the update server and defeat the certificate pinning protection could provide a malicious signed add-on instead of a valid update. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

An error in argument length checking in JavaScript, leading to potential integer overflows or other bounds checking issues. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

A heap-buffer-overflow in Cairo when processing SVG content caused by compiler optimization, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

The Mozilla Updater can be made to choose an arbitrary target working directory for output files resulting from the update process. This vulnerability requires local system access. Note: this issue only affects Windows operating systems. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

When the Mozilla Updater is run, if the Updater's log file in the working directory points to a hardlink, data can be appended to an arbitrary local file. This vulnerability requires local system access. Note: this issue only affects Windows operating systems. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

A same-origin policy bypass with local shortcut files to load arbitrary local content from disk. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.

Memory safety bugs were reported in Firefox 49 and Firefox ESR 45.4. 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 < 45.5, Firefox ESR < 45.5, and Firefox < 50.

Stack-based buffer overflow in the evutil_parse_sockaddr_port function in evutil.c in libevent before 2.1.6-beta allows attackers to cause a denial of service (segmentation fault) via vectors involving a long string in brackets in the ip_as_string argument.

Mozilla Firefox before 49.0, Firefox ESR 45.x before 45.4, and Thunderbird < 45.4 rely on unintended expiration dates for Preloaded Public Key Pinning, which allows man-in-the-middle attackers to spoof add-on updates by leveraging possession of an X.509 server certificate for addons.mozilla.org signed by an arbitrary built-in Certification Authority.

Use-after-free vulnerability in the DOMSVGLength class in Mozilla Firefox before 49.0, Firefox ESR 45.x before 45.4, and Thunderbird < 45.4 allows remote attackers to execute arbitrary code by leveraging improper interaction between JavaScript code and an SVG document.

Use-after-free vulnerability in the mozilla::nsTextNodeDirectionalityMap::RemoveElementFromMap function in Mozilla Firefox before 49.0, Firefox ESR 45.x before 45.4, and Thunderbird < 45.4 allows remote attackers to execute arbitrary code via bidirectional text.

Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 47.0 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors.