This indicates an attack attempt against a Cross-Site Scripting vulnerability in Nordex NC2.
The vulnerability is caused by a lack of sanitizing of the "username" parameter that is passed to "login". An attacker can exploit this by tricking an unsuspecting user into visiting a malicious webpage and execute arbitrary script code within the context of the application.
Nordex Control 2 (NC2) SCADA V16 and prior versions
System Compromise: Remote attackers can execute arbitrary script code within the context of the target user's browser.
Currently we are unaware of any vendor supplied patch for this issue.