A vulnerability has been identified in SIMATIC Drive Controller family (All versions), SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants) (All versions), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions < V20.8), SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants) (All versions >= V20.8), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions < V4.4.0), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions >= V4.4.0), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions < V2.8.1), SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions >= V2.8.1), SIMATIC S7-1500 Software Controller (All versions < V20.8), SIMATIC S7-1500 Software Controller (All versions >= V20.8), SIMATIC S7-PLCSIM Advanced (All versions < V3.0), SIMATIC S7-PLCSIM Advanced (All versions >= V3.0). An attacker with network access to port 102/tcp could potentially modify the user program on the PLC in a way that the running code is different from the source code which is stored on the device. An attacker must have network access to affected devices and must be able to perform changes to the user program. The vulnerability could impact the perceived integrity of the user program stored on the CPU. An engineer that tries to obtain the code of the user program running on the device, can receive different source code that is not actually running on the device.