Securing Embedded Systems

lock them in a white room.

Smart devices are popular, but they are a black box. The consumer usually has little ot no control over the technology being used within said smart devices, and vendors are known to be slow with rolling out security updates for their products. This makes all manners of smart devices attractive targets for hackers.

Static Devices

Keep the firmware updated. Even if it means updating the firmware manually. 

Minimizing Damage

If it's hard to update or you can't update the device reliably, consider isolating the device from the rest of the network using VLANs, and try to enable encryption on all home network communications.