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CVE-2014-8639

18
FAUCET Score

CVE-2014-8639 describes a session fixation vulnerability in Mozilla Firefox, Firefox ESR, Thunderbird, and SeaMonkey versions prior to their respective updates. The flaw allows remote HTTP proxy servers to conduct session fixation attacks by improperly interpreting Set-Cookie headers within 407 (Proxy Authentication Required) responses, enabling them to provide a cookie name matching the origin server's session cookie. With a CVSS score of 6.8, this vulnerability is of medium severity, requiring medium attack complexity and potentially leading to partial confidentiality, integrity, and availability impacts. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
<= 2.31CPE matchmatch criteria
cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
<= 34.0.5CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
31.0CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:31.0:*:*:*:*:*:*:*
31.1.0CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:31.1.0:*:*:*:*:*:*:*
31.1.1CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:31.1.1:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 2.0

6.8MEDIUM

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

Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Exploitability Score
8.6
Impact Score
6.4
CvssVersion
2.0

Exploit Intelligence

EPSS Score
1.90%
Probability of exploitation in next 30 days
EPSS Percentile
77.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0190 is in the 60th percentile among its peer group of 19,956 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (7)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6Fixed in: firefox-0:31.4.0-1.el6_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: firefox-0:31.4.0-1.el5_11
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: thunderbird-0:31.4.0-1.el5_11
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: xulrunner-0:31.4.0-1.el7_0
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6Fixed in: thunderbird-0:31.4.0-1.el6_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: firefox-0:31.4.0-1.el7_0
View patch
mozillavendor investigatingvia nvd_reference
View patch

Vendor Advisories (1)

redhatCVE-2014-8639Moderate

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

Jan 13, 2015

References

linux.oracle.com / errata/ELSA-2015-0046.html
linux.oracle.com / errata/ELSA-2015-0047.html
lists.opensuse.org / opensuse-security-announce/2015-01/msg00014.html
lists.opensuse.org / opensuse-security-announce/2015-01/msg00032.html
lists.opensuse.org / opensuse-security-announce/2015-01/msg00033.html
lists.opensuse.org / opensuse-security-announce/2015-01/msg00036.html
lists.opensuse.org / opensuse-security-announce/2015-02/msg00002.html
lists.opensuse.org / opensuse-security-announce/2015-07/msg00031.html
lists.opensuse.org / opensuse-updates/2015-01/msg00071.html
rhn.redhat.com / errata/RHSA-2015-0046.html
rhn.redhat.com / errata/RHSA-2015-0047.html
bugzilla.mozilla.org / show_bug.cgi
secunia.com / advisories/62237
secunia.com / advisories/62242
secunia.com / advisories/62250
secunia.com / advisories/62253
secunia.com / advisories/62259
secunia.com / advisories/62273
secunia.com / advisories/62274
secunia.com / advisories/62283
secunia.com / advisories/62293
secunia.com / advisories/62304
secunia.com / advisories/62313
secunia.com / advisories/62315
secunia.com / advisories/62316
secunia.com / advisories/62418
secunia.com / advisories/62446
secunia.com / advisories/62657
secunia.com / advisories/62790
exchange.xforce.ibmcloud.com / vulnerabilities/99959
security.gentoo.org / glsa/201504-01
debian.org / security/2015/dsa-3127
debian.org / security/2015/dsa-3132
mozilla.org / security/announce/2014/mfsa2015-04.html
Vendor Advisory
oracle.com / technetwork/topics/security/bulletinapr2015-2511959.html
securityfocus.com / bid/72046
securitytracker.com / id/1031533
securitytracker.com / id/1031534
ubuntu.com / usn/USN-2460-1