A vulnerability has been identified in SIMATIC NET PC Software V14 (All versions), SIMATIC NET PC Software V15 (All versions), SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions), SIMATIC PCS 7 V9.1 (All versions), SIMATIC WinCC (All versions < V8.0), SINAUT Software ST7sc (All versions). Before SIMATIC WinCC V8, legacy OPC services (OPC DA (Data Access), OPC HDA (Historical Data Access), and OPC AE (Alarms & Events)) were used per default. These services were designed on top of the Windows ActiveX and DCOM mechanisms and do not implement state-of-the-art security mechanisms for authentication and encryption of contents.