CVE-2009-3984

CVE-2009-3984 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, allows remote attackers to spoof an SSL indicator for an http URL or a file URL by setting document.location to an https URL corresponding to a site that responds with a No Content (aka 204) status code and an empty body.

Frequently asked questions

What is CVE-2009-3984?
Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, allows remote attackers to spoof an SSL indicator for an http URL or a file URL by setting document.location to an https URL corresponding to a site that responds with a No Content (aka 204) status code and an empty body.
How severe is CVE-2009-3984?
CVE-2009-3984 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2009-3984 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3984?
CVE-2009-3984 primarily affects Mozilla Firefox. In total, 157 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3984?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-3984 published?
CVE-2009-3984 was published on 2009-12-17 and last updated on 2026-06-16.

References

Affected products (157)

More vulnerabilities in Mozilla Firefox

All CVEs affecting Mozilla Firefox →