The STARTTLS implementation in SCO SCOoffice Server does not properly restrict I/O buffering, which allows man-in-the-middle attackers to insert commands into encrypted SMTP sessions by sending a cleartext command that is processed after TLS is in place, related to a "plaintext command injection" attack, a similar issue to CVE-2011-0411.
https://exchange.xforce.ibmcloud.com/vulnerabilities/65932
http://www.vupen.com/english/advisories/2011/0613
http://www.securityfocus.com/bid/46767