Keep biometric hardware on a separate VLAN to prevent unauthorized access from other office hardware.
Upload the firmware using the ZKTime.Net or BioTime software management suite.
Default passwords for ZKTeco devices are essentially public knowledge. Security researchers and documentation highlight several common combinations used across the platform: Root Access: Common pairs include root:solokey root:colorkey root:z1k2t3e4c5h Admin Access: Often defaults to admin:admin admin:1234 Web Interface: Default login is frequently administrator with the password Installation & User Guide - ZKTeco zmm220 default telnet password updated
If you are locked out, you may need to factory reset the device, which will restore the default administrative password ( 1234 or 123456 ), though this may not change the telnet password back.
2. ZMM220 Default Telnet Password Updated: The Current Situation (2026) Keep biometric hardware on a separate VLAN to
Securing the ZMM220 Biometric Platform: Default Telnet Password Updates and Firmware Hardening
with restricted access to the rest of the corporate network. Disable Unused Services: Disable Unused Services: | Device Age / Firmware
| Device Age / Firmware | Telnet Username | Default Password | |----------------------|----------------|------------------| | Pre-2024 (old firmware) | root | zmm220 (or blank) | | Post-update (v2.3.1+) | admin | Printed on device label (12-character alphanumeric) |
Many ZMM220 units received silent firmware updates that automatically reset default credentials and disabled weak protocols. The “updated” password is likely either:
For large deployments, create a spreadsheet mapping each device's serial number to its unique default password. Store this in an encrypted vault.