source: http://www.securityfocus.com/bid/8787/info

It has been reported that Medieval Total War may be prone to a denial of service vulnerability. The issue is caused when an attacker sends a malformed value for nickname consisting of 0 Unicode characters to the server during the initial authentication process. The exploitation of this issue results in the all users receiving a "Connection expired" message before leading to a crash of the server.

Successful exploitation of this issue may allow an attacker to cause the software to crash or hang.

Medieval Total War versions 1.1 and prior are reported to be prone to this vulnerability. 

http://www.exploit-db.com/sploits/23231.zip