Progea Movicon / PowerHMI 11.2.1085 and earlier allows remote attackers to cause a denial of service (memory corruption and crash) and possibly execute arbitrary code via an EIDP packet with a large size field, which writes a zero byte to an arbitrary memory location.
https://exchange.xforce.ibmcloud.com/vulnerabilities/69789
http://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-256-01.pdf