What are the consequences of having unprotected Linux operating systems installed on embedded systems?

highly venerable to external attacks

Explanation:

Embedded systems are the type of computer systems that are specially designed having hardware and software components plus programmable capabilities embedded into the hardware itself.

These computer systems are motorized by dedicated computer hardware chips made by companies such as Broadcom, Qualcomm, and Marvell. These chips are cheap which also means that they're highly vulnerable, and the profit margins slim. They normally put a version of the Linux operating system onto the chips, lumping it up with some other bunch of open-source and proprietary components and drivers. With little or no technical engineering work before shipping, and there's little enticement to update their "board support package" until there's probably a very good reason for it.