https://msrc.microsoft.com/update-guide/vulnerability/CVE-20...

States:

> Attack Vector: Network

> The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet.

The way I read it is MSPaint is now running as a service and listens to a port (while running? all the time?) and you can trigger remote execute by sending data. Just.. Why?..