Is CVE-2009-3639 actively exploited?

CVE-2009-3639 has no public evidence of in-the-wild exploitation as of 2025-04-09.

What is the CVSS score for CVE-2009-3639?

CVE-2009-3639 has a CVSS score of 5.8 (UNKNOWN severity). Vector: AV:N/AC:M/Au:N/C:N/I:P/A:P.

How do I patch CVE-2009-3639?

Patch guidance is available from proftpd security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2009-3639.

CVE-2009-3639 - remediation guidance & executive summary

Q: Which products are affected by CVE-2009-3639?

7 products: proftpd proftpd, proftpd proftpd, proftpd proftpd, proftpd proftpd, proftpd proftpd, and 2 more.

Description

The mod_tls module in ProFTPD before 1.3.2b, and 1.3.3 before 1.3.3rc2, when the dNSNameRequired TLS option is enabled, does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 client certificate, which allows remote attackers to bypass intended client-hostname restrictions via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

CVSS Metrics

Vector: AV:N/AC:M/Au:N/C:N/I:P/A:P
Access Vector: network
Access Cmplx: medium
Auth: none
Confidentiality: none
Integrity: partial
Availability: partial
Weaknesses: CWE-310

Metadata

Primary Vendor: PROFTPD
Published: 10/28/2009
Last Modified: 4/9/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

proftpd : proftpdproftpd : proftpdproftpd : proftpdproftpd : proftpdproftpd : proftpdproftpd : proftpdproftpd : proftpd

Remediation Guidance

Executive Summary

View on NIST NVD