Related Vulnerabilities: CVE-2016-5284  

Due to flaws in the process used to update "Preloaded Public Key Pinning", the pinning for add-on updates became ineffective in early September. An attacker who was able to get a mis-issued certificate for a Mozilla web site could send malicious add-on updates to users on networks controlled by the attacker. Users who have not installed any add-ons are not affected.

Severity High

Remote Yes

Type Certificate verification bypass

Description

Due to flaws in the process used to update "Preloaded Public Key Pinning", the pinning for add-on updates became ineffective in early September. An attacker who was able to get a mis-issued certificate for a Mozilla web site could send malicious add-on updates to users on networks controlled by the attacker. Users who have not installed any add-ons are not affected.

AVG-24 firefox 48.0.2-1 49.0-1 Critical Fixed

22 Sep 2016 ASA-201609-22 AVG-24 firefox Critical multiple issues

https://blog.mozilla.org/security/2016/09/16/update-on-add-on-pinning-vulnerability/
https://bugzilla.mozilla.org/show_bug.cgi?id=1303127