Debian Linux Security Advisory 1935-1 – Dan Kaminsky and Moxie Marlinspike discovered that gnutls, an implementation of the TLS/SSL protocol, does not properly handle a ‘ ’ character in a domain name in the subject’s Common Name or 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 Certification Authority. In addition, with this update, certificates with MD2 hash signatures are no longer accepted since they’re no longer considered cryptograhically secure.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/82738/dsa-1935-1.txt
Source: https://packetstormsecurity.com/files/82738/Debian-Linux-Security-Advisory-1935-1.html