CVE-2009-2479

CVE-2009-2479 is a high-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 7.8. Its EPSS exploit-prediction score of 12% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

Description

Mozilla Firefox 3.0.x, 3.5, and 3.5.1 on Windows allows remote attackers to cause a denial of service (uncaught exception and application crash) via a long Unicode string argument to the write method. NOTE: this was originally reported as a stack-based buffer overflow. NOTE: on Linux and Mac OS X, a crash resulting from this long string reportedly occurs in an operating-system library, not in Firefox.

Frequently asked questions

What is CVE-2009-2479?
Mozilla Firefox 3.0.x, 3.5, and 3.5.1 on Windows allows remote attackers to cause a denial of service (uncaught exception and application crash) via a long Unicode string argument to the write method. NOTE: this was originally reported as a stack-based buffer overflow. NOTE: on Linux and Mac OS X, a crash resulting from this long string reportedly occurs in an operating-system library, not in Firefox.
How severe is CVE-2009-2479?
CVE-2009-2479 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2009-2479 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 12% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2479?
CVE-2009-2479 primarily affects Mozilla Firefox. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-2479?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2009-2479 published?
CVE-2009-2479 was published on 2009-07-16 and last updated on 2026-06-16.

References

Affected products (19)

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