CVE-2009-3639: Medium severity proftpd vulnerability
modtls.c in ProFTPD 1.3.2a does not properly handle a '\0' character in a domain name in the subject's alternative name (subjectAltName) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.
Upstream bug report: -------------------- http://bugs.proftpd.org/showbug.cgi?id=3275
Upstream patch: --------------- http://bugs.proftpd.org/attachment.cgi?id=3096
Other sources
The modtls 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.
— MITRE
Affected Software
Remediation
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2009-3639?
The severity of CVE-2009-3639 is considered high due to potential exploitation by man-in-the-middle attackers.
How do I fix CVE-2009-3639?
To fix CVE-2009-3639, upgrade ProFTPD to version 1.3.3 or later, where the vulnerability has been addressed.
Who is affected by CVE-2009-3639?
CVE-2009-3639 affects ProFTPD versions up to and including 1.3.2 and certain release candidates.
What type of attack is possible with CVE-2009-3639?
CVE-2009-3639 allows attackers to perform man-in-the-middle attacks by spoofing arbitrary SSL servers.
What component of ProFTPD does CVE-2009-3639 impact?
CVE-2009-3639 impacts the mod_tls component in ProFTPD, specifically related to the handling of X.509 certificates.