A vulnerability has been identified in Firmware variant PROFINET IO for EN100 Ethernet module : All versions < V1.04.01; Firmware variant Modbus TCP for EN100 Ethernet module : All versions < V1.11.00; Firmware variant DNP3 TCP for EN100 Ethernet module : All versions < V1.03; Firmware variant IEC 104 for EN100 Ethernet module : All versions < V1.21; EN100 Ethernet module included in SIPROTEC Merging Unit 6MU80 : All versions < 1.02.02. Specially crafted packets sent to port 50000/UDP could cause a denial-of-service of the affected device. A manual reboot may be required to recover the service of the device.