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.
rhn.redhat.com/errata/RHSA-2016-1912.html
seclists.org/dailydave/2016/q3/51
www.debian.org/security/2016/dsa-3674
www.mozilla.org/security/announce/2016/mfsa2016-85.html
www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.html
www.securityfocus.com/bid/93049
www.securitytracker.com/id/1036852
blog.mozilla.org/security/2016/09/16/update-on-add-on-pinning-vulnerability/
bugzilla.mozilla.org/show_bug.cgi?id=1303127
hackernoon.com/tor-browser-exposed-anti-privacy-implantation-at-mass-scale-bd68e9eb1e95
security.gentoo.org/glsa/201701-15
www.mozilla.org/security/advisories/mfsa2016-86/
www.mozilla.org/security/advisories/mfsa2016-88/