CVE-2009-3987

CVE-2009-3987 is a high-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Description

The GeckoActiveXObject function in Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, generates different exception messages depending on whether the referenced COM object is listed in the registry, which allows remote attackers to obtain potentially sensitive information about installed software by making multiple calls that specify the ProgID values of different COM objects.

Frequently asked questions

What is CVE-2009-3987?
The GeckoActiveXObject function in Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, generates different exception messages depending on whether the referenced COM object is listed in the registry, which allows remote attackers to obtain potentially sensitive information about installed software by making multiple calls that specify the ProgID values of different COM objects.
How severe is CVE-2009-3987?
CVE-2009-3987 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2009-3987 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3987?
CVE-2009-3987 primarily affects Mozilla Firefox. In total, 156 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3987?
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-2009-3987 published?
CVE-2009-3987 was published on 2009-12-17 and last updated on 2026-06-16.

References

Affected products (156)

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