UpHeron
All vulnerabilities

Servers and applications

CVE-2009-3639

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…

Severity
Medium 5.8
Published
28 Oct 2009
Last changed
16 Jun 2026
Added to UpHeron
1 Nov 2026
Exploit chance
5.7% in the next 30 daysHigher than 93% of CVEs. EPSS by FIRST, 12 Nov 2026
Weakness
CWE-310
Attack
Over the network · No login needed
Attacker can
Change some data · Slow it down
CVSS vector
AV:N/AC:M/Au:N/C:N/I:P/A:P
Sources
NVD

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.

From NVD.

Affected software

SoftwareAffected versions
ProFTPDServers and applications · cpe:a:proftpd:proftpd
  • Version 1.3.3-rc1
  • Version 1.3.2
  • Version 1.3.2-rc4
  • Version 1.3.2-rc2
All 7 release lines
  • Every version up to 1.3.2
  • Version 1.3.1
  • Version 1.3.2-rc1
  • Version 1.3.2-rc2
  • Version 1.3.2-rc4
  • Version 1.3.2
  • Version 1.3.3-rc1

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2009-3639
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2009-3639