The remote web server contains several HTML form fields containing an input of type 'password' which transmit their information to a remote web server in cleartext. An attacker eavesdropping on the traffic between a web browser and server may obtain logins and passwords of valid users. (Source: Tenable Nessus)
Because the issue has low severity, users can assess their environments and decide if an update is needed.
This alert has come from: https://www.moxa.com/en/support/product-support/security-advisory/mpsa-252211-security-enhancement-web-server-transmits-cleartext-credentials