At least twenty eight backdoor accounts and other liabilities have been identified in the firmware of the FTTH ONT routers. These are widely implemented across Southeast Asia and South America. The Fiber-to-the-Home Optical Network Terminal consists of special devices that are present at the end of the optical fiber cables. Their main function is to transform optical cables sent through fiber optics cables to classic wireless (WiFI) or Ethernet connections.
As per reports, the engineers working with FiberHome had apparently failed to activate the protections for the IPv6 interface present in the routers that resulted in the liabilities and backdoors.
Source: zdnet