source: http://www.securityfocus.com/bid/27143/info

Pragma TelnetServer is prone to a denial-of-service vulnerability because it fails to adequately handle certain telnet options.

Attackers can leverage this issue to terminate the server and cause denial-of-service conditions.

This issue affects Pragma TelnetServer 7.0 Build 4 Revision 589; other versions may also be vulnerable.

https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/30991.zip