Vulnerability Monitor

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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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.4, indicating it can be exploited remotely over the network with relatively low complexity though user interaction is required and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 1 product from mozilla organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2016, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.

Published

2016-09-22T22:59:18.973

Last Modified

2025-04-12T10:46:40.837

Status

Deferred

Source

[email protected]

Severity

CVSSv3.0: 7.4 (HIGH)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:P/I:N/A:N

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: NONE
Availability Impact: NONE

Exploitability Score

8.6

Impact Score

2.9

Weaknesses

Type: Primary
CWE-20

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	mozilla	firefox	≤ 48.0.2	Yes
Application	mozilla	firefox	45.0	Yes
Application	mozilla	firefox	45.0.1	Yes
Application	mozilla	firefox	45.0.2	Yes
Application	mozilla	firefox	45.1.1	Yes
Application	mozilla	firefox	45.2.0	Yes
Application	mozilla	firefox	45.3.0	Yes

References

http://rhn.redhat.com/errata/RHSA-2016-1912.html ([email protected])
http://seclists.org/dailydave/2016/q3/51 Third Party Advisory ([email protected])
http://www.debian.org/security/2016/dsa-3674 ([email protected])
http://www.mozilla.org/security/announce/2016/mfsa2016-85.html Release Notes ([email protected])
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.html ([email protected])
http://www.securityfocus.com/bid/93049 ([email protected])
http://www.securitytracker.com/id/1036852 ([email protected])
https://blog.mozilla.org/security/2016/09/16/update-on-add-on-pinning-vulnerability/ Third Party Advisory, VDB Entry ([email protected])
https://bugzilla.mozilla.org/show_bug.cgi?id=1303127 Issue Tracking, Third Party Advisory, VDB Entry ([email protected])
https://hackernoon.com/tor-browser-exposed-anti-privacy-implantation-at-mass-scale-bd68e9eb1e95 Technical Description ([email protected])
https://security.gentoo.org/glsa/201701-15 ([email protected])
https://www.mozilla.org/security/advisories/mfsa2016-86/ ([email protected])
https://www.mozilla.org/security/advisories/mfsa2016-88/ ([email protected])
http://rhn.redhat.com/errata/RHSA-2016-1912.html (af854a3a-2127-422b-91ae-364da2661108)
http://seclists.org/dailydave/2016/q3/51 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://www.debian.org/security/2016/dsa-3674 (af854a3a-2127-422b-91ae-364da2661108)
http://www.mozilla.org/security/announce/2016/mfsa2016-85.html Release Notes (af854a3a-2127-422b-91ae-364da2661108)
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.html (af854a3a-2127-422b-91ae-364da2661108)
http://www.securityfocus.com/bid/93049 (af854a3a-2127-422b-91ae-364da2661108)
http://www.securitytracker.com/id/1036852 (af854a3a-2127-422b-91ae-364da2661108)
https://blog.mozilla.org/security/2016/09/16/update-on-add-on-pinning-vulnerability/ Third Party Advisory, VDB Entry (af854a3a-2127-422b-91ae-364da2661108)
https://bugzilla.mozilla.org/show_bug.cgi?id=1303127 Issue Tracking, Third Party Advisory, VDB Entry (af854a3a-2127-422b-91ae-364da2661108)
https://hackernoon.com/tor-browser-exposed-anti-privacy-implantation-at-mass-scale-bd68e9eb1e95 Technical Description (af854a3a-2127-422b-91ae-364da2661108)
https://security.gentoo.org/glsa/201701-15 (af854a3a-2127-422b-91ae-364da2661108)
https://www.mozilla.org/security/advisories/mfsa2016-86/ (af854a3a-2127-422b-91ae-364da2661108)
https://www.mozilla.org/security/advisories/mfsa2016-88/ (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For mozilla's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.