Skip to content
Fencer Intel
medium 6.8

CVE-2014-8639 json

Mozilla Firefox before 35.0, Firefox ESR 31.x before 31.4, Thunderbird before 31.4, and SeaMonkey before 2.32 do not properly interpret Set…

published 2015-01-14 11 y ago modified 2026-06-17 4 mo ago also EUVD-2014-8476

cvss
6.8
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits
0
none known

Summary

Mozilla Firefox before 35.0, Firefox ESR 31.x before 31.4, Thunderbird before 31.4, and SeaMonkey before 2.32 do not properly interpret Set-Cookie headers within responses that have a 407 (aka Proxy Authentication Required) status code, which allows remote HTTP proxy servers to conduct session fixation attacks by providing a cookie name that corresponds to the session cookie of the origin server.

Patch / fix

  • firefox Ubuntu 14.04 LTS 35.0+build3-0ubuntu0.14.04.2
  • thunderbird Ubuntu 14.04 LTS 1:31.4.0+build1-0ubuntu0.14.04.1

ubuntu advisories UBUNTU-CVE-2014-8639

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 31.4.0-1.el5_11
  • thunderbird RHEL 6 31.4.0-1.el6_6
  • firefox RHEL 5 31.4.0-1.el5_11
  • firefox RHEL 6 31.4.0-1.el6_6
  • firefox RHEL 7 31.4.0-1.el7_0
  • xulrunner RHEL 7 31.4.0-1.el7_0

red hat advisories RHSA-2015:0047RHSA-2015:0046

  • 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-2014-8639 updated cvss 4.3

Mozilla: Cookie injection through Proxy Authenticate responses (MFSA 2015-04)

  • Red Hat Enterprise Linux (v. 5 server) firefox 31.4.0-1.el5_11 Red Hat Enterprise Linux Client (v. 7) firefox 31.4.0-1.el7_0, xulrunner 31.4.0-1.el7_0 Red Hat Enterprise Linux Client Optional (v. 7) firefox 31.4.0-1.el7_0 Red Hat Enterprise Linux ComputeNode Optional (v. 7) xulrunner 31.4.0-1.el7_0 Red Hat Enterprise Linux Desktop (v. 5 client) firefox 31.4.0-1.el5_11, thunderbird 31.4.0-1.el5_11 Red Hat Enterprise Linux Desktop (v. 6) firefox 31.4.0-1.el6_6, thunderbird 31.4.0-1.el6_6
    +2 more products
    Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 31.4.0-1.el6_6 Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 31.4.0-1.el6_6
    fixed: vendor fix RHSA-2015:0046
  • Red Hat Enterprise Linux Optional Productivity Applications (v. 5 server) thunderbird 31.4.0-1.el5_11
    fixed: vendor fix RHSA-2015:0047
  • Red Hat Enterprise Linux Server (v. 6) firefox 31.4.0-1.el6_6 Red Hat Enterprise Linux Server (v. 7) firefox 31.4.0-1.el7_0, xulrunner 31.4.0-1.el7_0 Red Hat Enterprise Linux Server Optional (v. 6) firefox 31.4.0-1.el6_6, thunderbird 31.4.0-1.el6_6 Red Hat Enterprise Linux Server Optional (v. 7) firefox 31.4.0-1.el7_0, xulrunner 31.4.0-1.el7_0 Red Hat Enterprise Linux Workstation (v. 6) firefox 31.4.0-1.el6_6, thunderbird 31.4.0-1.el6_6 Red Hat Enterprise Linux Workstation (v. 7) firefox 31.4.0-1.el7_0, xulrunner 31.4.0-1.el7_0
    +2 more products
    Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 31.4.0-1.el6_6 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 31.4.0-1.el7_0
    fixed: vendor fix RHSA-2015:0046

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

1.90% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

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.