CVE-2009-3287

CVE-2009-3287 is a high-severity vulnerability in Macournoyer Thin with a CVSS 2.0 base score of 7.5. 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-20.

Key facts

Description

lib/thin/connection.rb in Thin web server before 1.2.4 relies on the X-Forwarded-For header to determine the IP address of the client, which allows remote attackers to spoof the IP address and hide activities via a modified X-Forwarded-For header.

Frequently asked questions

What is CVE-2009-3287?
lib/thin/connection.rb in Thin web server before 1.2.4 relies on the X-Forwarded-For header to determine the IP address of the client, which allows remote attackers to spoof the IP address and hide activities via a modified X-Forwarded-For header.
How severe is CVE-2009-3287?
CVE-2009-3287 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-2009-3287 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3287?
CVE-2009-3287 primarily affects Macournoyer Thin. In total, 21 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3287?
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-2009-3287 published?
CVE-2009-3287 was published on 2009-09-22 and last updated on 2026-06-16.

References

Affected products (21)

Other CWE-20 (Improper Input Validation) vulnerabilities

Browse all CWE-20 (Improper Input Validation) vulnerabilities →