An exploitable heap buffer overflow vulnerability exists in the iocheckd service I/O-Check functionality of WAGO PFC200 Firmware version 03.01.07(13), WAGO PFC200 Firmware version 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a heap buffer overflow, potentially resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.