The official manual said they were managed via a proprietary cloud platform. The cloud was ash now. But Sasha, a former firmware engineer for the very company that built the ZMM220, knew the secret.
Many of these devices use (Telnet, HTTP) and hardcoded credentials, making them highly vulnerable to network-based attacks. It is strongly recommended to: Disable Telnet if not actively needed for maintenance.
ZMM220 Platform / Embedded Devices Service: Telnet (Port 23) Vulnerability Type: Use of Default/Hardcoded Credentials CVSS Score: 9.8 (Critical)
Before we hunt for the password, we must understand the prey. The ZMM220 is not a single consumer router from a major brand like Asus or Netgear. Instead, it is typically a reference design or a pre-certified wireless module based on the or a similar MIPS-based SoC (System on a Chip).
Telnet is typically disabled by default on recent firmware for security reasons. To enable it: