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CVE-2009-2477

69
FAUCET Score

CVE-2009-2477 describes a critical arbitrary code execution vulnerability in Mozilla Firefox 3.5 prior to version 3.5.1, specifically within the Just-in-time (JIT) JavaScript compiler (TraceMonkey). This flaw allows remote attackers to execute arbitrary code by manipulating the escape function, leading to access of uninitialized memory locations. With a CVSS score of 9.3, it represents a network-exploitable vulnerability with medium attack complexity, resulting in complete compromise of confidentiality, integrity, and availability. Exploit intelligence indicates the existence of Metasploit modules and several ExploitDB entries, including heap spray techniques, confirming the availability of exploit code. Despite the high EPSS score and FAUCET Risk Score of 99/100, there is no evidence of active exploitation in the KEV catalog, and community discussion and media coverage are minimal.

Impacted Technologies

VendorProductVersion(s)CPE
3.5CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:3.5:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 2.0

9.3HIGH

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

Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Exploitability Score
8.6
Impact Score
10.0
CvssVersion
2.0

Exploit Intelligence

EPSS Score
42.69%
Probability of exploitation in next 30 days
EPSS Percentile
98.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
Metasploit: Firefox 3.5 escape() Return Value Memory Corruption · Jul 13, 2009
ExploitDB: EDB-40936 · Dec 18, 2016
This CVE's current EPSS score of 0.4269 is in the 97th percentile among its peer group of 8,920 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

mozillapatch availablevia nvd_reference
View patch

Vendor Advisories (1)

redhatCVE-2009-2477Critical

firefox 3.5 various flaws

Jul 14, 2009

References

blog.mozilla.com / security/2009/07/14/critical-javascript-vulnerability-in-firefox-35
isc.sans.org / diary.html
bugzilla.mozilla.org / show_bug.cgi
secunia.com / advisories/35798
Vendor Advisory
sunsolve.sun.com / search/document.do
exploit-db.com / exploits/40936
redhat.com / archives/fedora-package-announce/2009-July/msg00909.html
voices.washingtonpost.com / securityfix/2009/07/stopgap_fix_for_critical_firef.html
exploit-db.com / exploits/9137
exploit-db.com / exploits/9181
h-online.com / security/First-Zero-Day-Exploit-for-Firefox-3-5--/news/113761
kb.cert.org / vuls/id/443060
US Government Resource
mozilla.org / security/announce/2009/mfsa2009-41.html
PatchVendor Advisory
securityfocus.com / bid/35660
Exploit
vupen.com / english/advisories/2009/1868
PatchVendor Advisory