A TCL Smart TV running a vulnerable UPnP/DLNA MediaRenderer implementation is affected by a remote, unauthenticated Denial of Service (DoS) condition. By sending a flood of malformed or oversized SetAVTransportURI SOAP requests to the UPnP control endpoint, an attacker can cause the device to become unresponsive. This denial persists as long as the attack continues and affects all forms of TV operation. Manual user control and even reboots do not restore functionality unless the flood stops.
The product does not properly control the allocation and maintenance of a limited resource.
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.