Stack-based buffer overflow in HmiLoad in the runtime loader in Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP, Comfort Panels, and Mobile Panels SIMATIC HMI panels; WinCC V11 Runtime Advanced; and WinCC flexible Runtime, when Transfer Mode is enabled, allows remote attackers to execute arbitrary code via vectors related to Unicode strings.
https://exchange.xforce.ibmcloud.com/vulnerabilities/71449
http://www.us-cert.gov/control_systems/pdf/ICSA-12-030-01.pdf
http://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-332-02A.pdf
http://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-332-02.pdf