A buffer overflow exists in the ESMTP CMailServer 4.0.2002.11.24 SMTP Service, resulting in a denial of service attack. It is possible to overwrite the exception handler on the stack allowing a system compromise with code execution running as SYSTEM.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/31121/cmail-vuln.txt
Source: https://packetstormsecurity.com/files/31121/cmail-vuln.txt.html