Modicon M221 Security Notification – CVE-2018-7798

This document details a high-severity vulnerability (CVE-2018-7798) in Schneider Electric's Modicon M221 PLC, which allows remote attackers to change the device's IPv4 configuration due to insufficient verification of data authenticity. It provides remediation steps, including firewall configuration and disabling unused protocols, along with general cybersecurity best practices for industrial control systems.