Improper input validation in Mozilla Firefox

CVE-2016-5284

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.024 (82.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2016-5284?
CVE-2016-5284 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Input Validation. CVSS score: 7.4/10. Published 2016-09-22.
How severe is CVE-2016-5284?
High severity. CVSS v3 base score is 7.4 out of 10.
Is CVE-2016-5284 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.