To exploit this vulnerability, the attacker sends data from the GotoCmd argument to control. If the value of the argument is overly long, the static stack buffer can be overflowed. This will allow the attacker to execute arbitrary code remotely.
https://www.cisa.gov/news-events/ics-advisories/icsa-14-079-03
http://www.securityfocus.com/bid/66740
http://www.securityfocus.com/bid/66722