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Fencer Intel
medium 4.3

CVE-2015-2741 json

Mozilla Firefox before 39.0, Firefox ESR 38.x before 38.1, and Thunderbird before 38.1 do not enforce key pinning upon encountering an X.50…

published 2015-07-06 11 y ago modified 2026-06-17 4 mo ago also EUVD-2015-2831

cvss
4.3
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

Mozilla Firefox before 39.0, Firefox ESR 38.x before 38.1, and Thunderbird before 38.1 do not enforce key pinning upon encountering an X.509 certificate problem that generates a user dialog, which allows user-assisted man-in-the-middle attackers to bypass intended access restrictions by triggering a (1) expired certificate or (2) mismatched hostname for a domain with pinning enabled.

Patch / fix

  • firefox Ubuntu 14.04 LTS 39.0+build5-0ubuntu0.14.04.1
  • thunderbird Ubuntu 14.04 LTS 1:31.8.0+build1-0ubuntu0.14.04.1

ubuntu advisories UBUNTU-CVE-2015-2741

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 5 PRODUCTIVITY, RHEL 5 31.8.0-1.el5_11
  • thunderbird RHEL 6 31.8.0-1.el6_6
  • thunderbird RHEL 7 31.8.0-1.el7_1
  • thunderbird RHEL 7 31.8.0-1.ael7b_1
  • firefox RHEL 5 38.1.0-1.el5_11
  • firefox RHEL 6 38.1.0-1.el6_6
  • firefox RHEL 7 38.1.0-1.el7_1

red hat advisories RHSA-2015:1455RHSA-2015:1207

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1
  • MozillaThunderbird openSUSE Tumbleweed 45.5.1-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10071-1openSUSE-SU-2024:10230-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-2741 updated cvss 4.3

Mozilla: Key pinning is ignored when overridable errors are encountered (MFSA 2015-67)

  • Red Hat Enterprise Linux (v. 5 server) firefox 38.1.0-1.el5_11 Red Hat Enterprise Linux Client (v. 7) firefox 38.1.0-1.el7_1, thunderbird 31.8.0-1.el7_1 Red Hat Enterprise Linux Client Optional (v. 7) firefox 38.1.0-1.el7_1 Red Hat Enterprise Linux Desktop (v. 5 client) firefox 38.1.0-1.el5_11, thunderbird 31.8.0-1.el5_11 Red Hat Enterprise Linux Desktop (v. 6) firefox 38.1.0-1.el6_6, thunderbird 31.8.0-1.el6_6 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 38.1.0-1.el6_6
    +1 more products
    Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 38.1.0-1.el6_6
    fixed: vendor fix RHSA-2015:1207
  • Red Hat Enterprise Linux Optional Productivity Applications (v. 5 server) thunderbird 31.8.0-1.el5_11
    fixed: vendor fix RHSA-2015:1455
  • Red Hat Enterprise Linux Server (v. 6) firefox 38.1.0-1.el6_6 Red Hat Enterprise Linux Server (v. 7) firefox 38.1.0-1.el7_1, firefox 38.1.0-1.ael7b_1 Red Hat Enterprise Linux Server Optional (v. 6) firefox 38.1.0-1.el6_6, thunderbird 31.8.0-1.el6_6 Red Hat Enterprise Linux Server Optional (v. 7) firefox 38.1.0-1.el7_1, thunderbird 31.8.0-1.el7_1, thunderbird 31.8.0-1.ael7b_1 Red Hat Enterprise Linux Workstation (v. 6) firefox 38.1.0-1.el6_6, thunderbird 31.8.0-1.el6_6 Red Hat Enterprise Linux Workstation (v. 7) firefox 38.1.0-1.el7_1, thunderbird 31.8.0-1.el7_1
    +2 more products
    Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 38.1.0-1.el6_6 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 38.1.0-1.el7_1
    fixed: vendor fix RHSA-2015:1207

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.31% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.