{"cve":"CVE-2009-3639","nvd":{"published":"2009-10-28T14:30:00.217","modified":"2026-06-16T23:12:04.440","status":"Modified","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_v4":null,"cvss_v3":null,"cwes":["CWE-310"],"references":["http://bugs.proftpd.org/show_bug.cgi?id=3275","http://marc.info/?l=oss-security&m=125630966510672&w=2","http://marc.info/?l=oss-security&m=125632960508211&w=2","http://secunia.com/advisories/37131","http://secunia.com/advisories/37219"],"products":["proftpd:proftpd"],"source":"nvd","synced_at":"2026-10-19T19:54:26.868835795+00:00"},"epss":{"cve":"CVE-2009-3639","score":0.057,"percentile":0.9301,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}