Datto Backup Agent 1.0.6.0 and earlier does not authenticate incoming connections. This allows an attacker to impersonate a Datto Backup Appliance to "pair" with the agent and issue requests to this agent, if the attacker can reach the agent on TCP port 25566 or 25568, and send unspecified "specific information" by which the agent identifies a network device that is "appearing to be a valid Datto."