WS FTP uses a binary protocol to speak to the logging daemon, and each transmission begins with a two byte header "0xab 0xaa". If using a long string of characters to mangle the remaining portions of the message, a pointer operation fails. This crashes the process. By flipping two bytes immediately after the two primary header bytes, you are also able to control where the dereferencing address is at the time of the crash. However, this doesnot appear to allow code execution on the remote host as the address referenced is too far away from any user supplied input.
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