Debian Linux Security Advisory 1985-1 – It was discovered that sendmail, a Mail Transport Agent, does not properly handle a ‘ ’ character in a Common Name (CN) field of an X.509 certificate. This allows an attacker to spoof arbitrary SSL-based SMTP servers via a crafted server certificate issued by a legitimate Certification Authority, and to bypass intended access restrictions via a crafted client certificate issued by a legitimate Certification Authority.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/85800/dsa-1985-1.txt
Source: https://packetstormsecurity.com/files/85800/Debian-Linux-Security-Advisory-1985-1.html