Buffer overflow in the DiagAgent web server in Siemens WinCC 7.0 SP3 through Update 2 allows remote attackers to cause a denial of service (agent outage) via crafted input.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2012-2584
http://www.us-cert.gov/control_systems/pdf/ICSA-12-158-01.pdf