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CVE-2012-4203

23
FAUCET Score

CVE-2012-4203 describes a vulnerability in Mozilla Firefox versions prior to 17.0 where the New Tab page allowed JavaScript code from bookmarklets to execute in a privileged context. This flaw enabled user-assisted remote attackers to run arbitrary programs by exploiting a javascript: URL within a bookmark. With a CVSS score of 6.8, this vulnerability has a medium severity, requiring user interaction (AC:M) but potentially leading to partial confidentiality, integrity, and availability compromise (C:P/I:P/A:P). There is no evidence of active exploitation, nor are there known public exploit tools like Metasploit or Nuclei, and it has received minimal community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
<= 16.0.2CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
0.1CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:0.1:*:*:*:*:*:*:*
0.2CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:0.2:*:*:*:*:*:*:*
0.3CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:0.3:*:*:*:*:*:*:*
0.4CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:0.4:*:*:*:*:*:*:*

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
3.26%
Probability of exploitation in next 30 days
EPSS Percentile
87.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0326 is in the 81st percentile among its peer group of 19,955 CVEs.

Social Chatter

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

Vendor Patches (1)

mozillavendor investigatingvia nvd_reference
View patch

Vendor Advisories (1)

redhatCVE-2012-4203Moderate

Mozilla: Javascript: URLs run in privileged context on New Tab page (MFSA 2012-95)

Nov 20, 2012

References

lists.opensuse.org / opensuse-security-announce/2012-11/msg00021.html
lists.opensuse.org / opensuse-security-announce/2013-01/msg00022.html
lists.opensuse.org / opensuse-updates/2012-11/msg00090.html
lists.opensuse.org / opensuse-updates/2012-11/msg00093.html
bugzilla.mozilla.org / show_bug.cgi
secunia.com / advisories/51369
secunia.com / advisories/51434
secunia.com / advisories/51439
oval.cisecurity.org / repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16503
mozilla.org / security/announce/2012/mfsa2012-95.html
Vendor Advisory
securityfocus.com / bid/56623
ubuntu.com / usn/USN-1638-1
ubuntu.com / usn/USN-1638-2
ubuntu.com / usn/USN-1638-3