Actu
Vigil@nce: ProFTPD, truncation of X.509 with null
October 2009 by Vigil@nce
When ProFTPD uses the mod_tls module, an attacker can send a X.509
certificate with a subjectAltName field containing a null
character, in order to bypass access restrictions.
Severity: 2/4
Consequences: data reading
Provenance: internet client
Means of attack: no proof of concept, no attack
Ability of attacker: expert (4/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 21/10/2009
IMPACTED PRODUCTS
– Mandriva Corporate
– Mandriva Enterprise Server
– Mandriva Linux
– ProFTPD
DESCRIPTION OF THE VULNERABILITY
The mod_tls module of ProFTPD checks the X.509 certificate sent by
the client.
However, when a X.509 certificate contains a null character in the
Subject Alternate Name field, mod_tls truncates this field. This
vulnerability is similar to VIGILANCE-VUL-8908
(https://vigilance.fr/tree/1/8908), even if the vulnerable source
code is different.
When ProFTPD uses the mod_tls module, an attacker can therefore
send a X.509 certificate with a subjectAltName field containing a
null character, in order to bypass access restrictions.
CHARACTERISTICS
Identifiers: 3275, CVE-2009-3639, MDVSA-2009:288,
VIGILANCE-VUL-9107
http://vigilance.fr/vulnerability/ProFTPD-truncation-of-X-509-with-null-9107
