Description
The Public Key Pinning (PKP) implementation in Mozilla Firefox before 33.0 does not properly consider the connection-coalescing behavior of SPDY and HTTP/2 in the case of a shared IP address, which allows man-in-the-middle attackers to bypass an intended pinning configuration and spoof a web site by providing a valid certificate from an arbitrary recognized Certification Authority.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | firefox | 33.0+build2-0ubuntu0.14.04.1 | USN-2372-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 50.1.0-1.1 | openSUSE-SU-2024:10071-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Advisories 3
- USN-2372-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10071-1 MozillaFirefox-50.1.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1049095
- openSUSE-SU-2014:1344 vendor-advisory
- FEDORA-2014-13042 vendor-advisory
- http://www.mozilla.org/security/announce/2014/mfsa2014-80.html
- 1031028 vdb-entry
- openSUSE-SU-2014:1345 vendor-advisory
- GLSA-201504-01 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- FEDORA-2014-14084 vendor-advisory
- USN-2372-1 vendor-advisory
- 62022 third-party-advisory
- 62023 third-party-advisory
- 70432 vdb-entry