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.
https://www.mozilla.org/security/advisories/mfsa2016-93/
https://www.mozilla.org/security/advisories/mfsa2016-90/
https://www.mozilla.org/security/advisories/mfsa2016-89/
https://www.debian.org/security/2016/dsa-3730
https://security.gentoo.org/glsa/201701-15
http://www.securitytracker.com/id/1037298