An issue was discovered on Mofi Network MOFI4500-4GXeLTE 4.1.5-std devices. The Dropbear SSH daemon has been modified to accept an alternate hard-coded path to a public key that allows root access. This key is stored in a /rom location that cannot be modified by the device owner.
https://www.criticalstart.com/critical-vulnerabilities-discovered-in-mofi-routers/