CVE-2013-0776

Mozilla Firefox before 19.0, Firefox ESR 17.x before 17.0.3, Thunderbird before 17.0.3, Thunderbird ESR 17.x before 17.0.3, and SeaMonkey before 2.16 allow man-in-the-middle attackers to spoof the address bar by operating a proxy server that provides a 407 HTTP status code accompanied by web script, as demonstrated by a phishing attack on an HTTPS site.

Published: 2013-02-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2013-0776 is rated Moderate Risk (40/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.30%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2013-0776

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.65% 1.30% +0.65%
2 2025-03-30 1.33% 0.65% -0.68%
3 2025-03-29 — 1.33% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2013-0776

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.0 2.0 MEDIUM
AV:N/AC:H/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 4.9 4.9 [email protected]

Weakness enumeration for CVE-2013-0776

OS Trackers for CVE-2013-0776

vendor priority summary link
gentoo high CVE-2013-0776: 1 GLSA(s) (201309-23), 6 atom(s) (mail-client/thunderbird, mail-client/thunderbird-bin, www-client/firefox, www-client/firefox-bin, www-client/seamonkey, www-client/seamonkey-bin); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2013-0776
redhat medium — https://access.redhat.com/security/cve/CVE-2013-0776
suse medium CVE-2013-0776 severity moderate: SUSE including 98 source package names (MozillaFirefox, MozillaFirefox-140.2.0-160000.1.2, …), 138 product×package rows across 35 product lines (SUSE Linux Enterprise Desktop 11 SP2, SUSE Linux Enterprise Desktop 12, … (35 product lines)): Fixed 137, Known Not Affected 1. https://www.suse.com/security/cve/CVE-2013-0776/
ubuntu medium CVE-2013-0776 medium priority: Ubuntu including 5 source packages (firefox, seamonkey, thunderbird, xulrunner-1.9.2, xulrunner-2.0), 40 status rows across 8 suites (hardy, lucid, oneiric, precise, quantal, raring, saucy, upstream): DNE 16, released 11, ignored 7, not-affected 4, needs-triage 2. https://ubuntu.com/security/CVE-2013-0776

Affected software / configurations for CVE-2013-0776

Vendor Product Version Raw CPE
mozilla firefox < 17.0.3 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox < 19.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla seamonkey < 2.16 cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
mozilla thunderbird < 17.0.3 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
mozilla thunderbird_esr < 17.0.3 cpe:2.3:a:mozilla:thunderbird_esr:*:*:*:*:*:*:*:*
opensuse opensuse 11.4 cpe:2.3:o:opensuse:opensuse:11.4:*:*:*:*:*:*:*
opensuse opensuse 12.1 cpe:2.3:o:opensuse:opensuse:12.1:*:*:*:*:*:*:*
opensuse opensuse 12.2 cpe:2.3:o:opensuse:opensuse:12.2:*:*:*:*:*:*:*
redhat enterprise_linux_aus 5.9 cpe:2.3:o:redhat:enterprise_linux_aus:5.9:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 5.0 cpe:2.3:o:redhat:enterprise_linux_desktop:5.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 5.9 cpe:2.3:o:redhat:enterprise_linux_eus:5.9:*:*:*:*:*:*:*
redhat enterprise_linux_eus 6.3 cpe:2.3:o:redhat:enterprise_linux_eus:6.3:*:*:*:*:*:*:*
redhat enterprise_linux_server 5.0 cpe:2.3:o:redhat:enterprise_linux_server:5.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 5.0 cpe:2.3:o:redhat:enterprise_linux_workstation:5.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
canonical ubuntu_linux 10.04 cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:*
canonical ubuntu_linux 11.10 cpe:2.3:o:canonical:ubuntu_linux:11.10:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 12.10 cpe:2.3:o:canonical:ubuntu_linux:12.10:*:*:*:*:*:*:*

References for CVE-2013-0776

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2013-02/msg00017.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-updates/2013-02/msg00062.html Mailing List Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2013-0271.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2013-0272.html Third Party Advisory
http://www.debian.org/security/2013/dsa-2699 Third Party Advisory
http://www.mozilla.org/security/announce/2013/mfsa2013-27.html Vendor Advisory
http://www.ubuntu.com/usn/USN-1729-1 Third Party Advisory
http://www.ubuntu.com/usn/USN-1729-2 Third Party Advisory
http://www.ubuntu.com/usn/USN-1748-1 Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=796475 Issue Tracking Patch Vendor Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16666 Third Party Advisory
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