For years, the security team had flagged it as a "low-risk" exception. "It's behind the firewall," they said. "No one will ever guess."

Use the passwd command immediately.

The update to the default Telnet password was made to address several concerns:

Access the device web panel by entering its IP in a browser (often port 80 or 4370). Log in (default is often administrator Navigate to Network Settings System Settings Look for a toggle and set it to Important: Firmware Updates

: Security experts have identified that some ZMM220 firmware versions use a hidden telnet password stored in the configuration file as $Telnet=z1k2t3e4c5h .