** libgnutls: Fix problem with NUL bytes in X.509 CN and SAN fields.
By using a NUL byte in CN/SAN fields, it was possible to fool GnuTLS
into 1) not printing the entire CN/SAN field value when printing a
certificate and 2) cause incorrect positive matches when matching a
hostname against a certificate. Some CAs apparently have poor
checking of CN/SAN values and issue these (arguable invalid)
certificates. Combined, this can be used by attackers to become a
MITM on server-authenticated TLS sessions. The problem is mitigated
since attackers needs to get one certificate per site they want to
attack, and the attacker reveals his tracks by applying for a
certificate at the CA. It does not apply to client authenticated TLS
sessions. Research presented independently by Dan Kaminsky and Moxie
Marlinspike at BlackHat09. Thanks to Tomas Hoger <thoger <at> redhat.com>
for providing one part of the patch. [GNUTLS-SA-2009-4].
libgnutls in GnuTLS before 2.8.2 does not properly handle a '\0'
character in a domain name in the subject's (1) Common Name (CN) or
(2) Subject Alternative Name (SAN) 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
AFAIK a lot of software (e.g. rsyslogd) uses gnutls. That's why, I vote YES.
YES too, request filed.
This issue was resolved and addressed in
GLSA 201206-18 at http://security.gentoo.org/glsa/glsa-201206-18.xml
by GLSA coordinator Sean Amoss (ackle).