An exploitable improper host validation vulnerability exists in the Cloud Connectivity functionality of WAGO PFC200 Firmware versions 03.02.02(14), 03.01.07(13), and 03.00.39(12). A specially crafted HTTPS POST request can cause the software to connect to an unauthorized host, resulting in unauthorized access to firmware update functionality. An attacker can send an authenticated HTTPS POST request to direct the Cloud Connectivity software to connect to an attacker controlled Azure IoT Hub node.