An Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 allowing an attacker to send a specially crafted URL to a currently authenticated web server user to execute a password change on the web server.
https://www.tenable.com/security/research/tra-2018-38
https://www.schneider-electric.com/en/download/document/SEVD-2018-327-01/