A vulnerability has been identified in EN100 Ethernet module DNP3 variant (All versions), EN100 Ethernet module IEC 61850 variant (All versions < V4.37), EN100 Ethernet module IEC104 variant (All versions), EN100 Ethernet module Modbus TCP variant (All versions), EN100 Ethernet module PROFINET IO variant (All versions). An unauthorized user could exploit a buffer overflow vulnerability in the webserver. Specially crafted packets sent could cause a Denial-of-Service condition and if certain conditions are met, the affected devices must be restarted manually to fully recover. At the time of advisory publication no public exploitation of this security vulnerability was known.