CVE-2016-5284: Input Validation
Due to flaws in the process we used to update "Preloaded Public Key Pinning" in our releases, 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.
Other sources
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.
— Launchpad
Affected Software
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is CVE-2016-5284?
CVE-2016-5284 is a vulnerability in Mozilla Firefox and Thunderbird that allows attackers to send malicious add-on updates to users.
How does CVE-2016-5284 affect Mozilla Firefox?
CVE-2016-5284 affects Mozilla Firefox versions up to and including 48.0.2, Firefox ESR versions up to and including 45.4, and Thunderbird versions up to and including 45.4.
What is the severity of CVE-2016-5284?
CVE-2016-5284 has a severity rating of 7 (high).
How can I fix CVE-2016-5284?
To fix CVE-2016-5284, update Mozilla Firefox to version 49.0 or later, Firefox ESR to version 45.4 or later, or Thunderbird to version 45.4 or later.
Where can I find more information about CVE-2016-5284?
You can find more information about CVE-2016-5284 on the Mozilla Bugzilla website, Mozilla security advisories page, and Red Hat Errata page.