: For some devices, such as the Siemens LOGO! 8 , if a custom password is forgotten, there is often no "backdoor." The only solution is to delete the entire program and start from scratch, which underscores the high stakes of losing these keys.

Gone are the days of a single password. Today's HMIs and PLCs use a multi-layered approach to access control.

Capturing the data packets transmitted between the programming software and the hardware during a login attempt, as some older protocols send password strings unencrypted.

Restrict access so that operators cannot access PLC engineering software.

If an engineer cannot upload the project file from the HMI due to a password prompt, specialized software can exploit the HMI's transfer protocol to bypass the prompt and pull the compiled runtime file.