--- title: "CVE-2009-3639\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2009-3639?format=md keywords: index, follow --- # CVE-2009-3639 Publication date 28 October 2009 Last updated 24 July 2024 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) Toggle side navigation ## 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. ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | proftpd-dfsg | 11.10 oneiric | Not affected | | 11.04 natty | Not affected | | 10.10 maverick | Not affected | | 10.04 LTS lucid | Not affected | | 9.10 karmic | Ignored end of life | | 9.04 jaunty | Ignored end of life | | 8.10 intrepid | Ignored end of life, was needed | | 8.04 LTS hardy | Ignored end of life | | 6.06 LTS dapper | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3639) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2009-3639) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2009-3639) * [Debian](https://security-tracker.debian.org/tracker/CVE-2009-3639) ### Other references *