MELSEC-Q Ethernet Interface Module Security Technical Bulletin

This technical bulletin addresses security vulnerabilities in Mitsubishi Electric MELSEC-Q series Ethernet interface modules (models QJ71E71-100, QJ71E71-B5, QJ71E71-B2) that could allow unauthorized access, program upload/download, and TCP/IP communication disruption if directly connected to the Internet without a firewall. It recommends user measures such as installing firewalls, checking Internet connections, and introduces an IP filter function (available on modules with serial numbers starting "18072" or later) to enhance security by restricting access based on source IP addresses.