Sounds like it might be opening a file that was sent over the network without any user interaction.

That's... that's not RCE though.

Yes, it is.

Reading tea leaves is still reading tea leaves, even if you make an AI do it… (which is what this is, judging by other things I've seen on opencve.io)

Yeah, OpenCVE also includes this:

> After applying the update, verify that the target Windows systems are running a version that includes the CVE fix before disabling legacy file‑open processing in Paint.

Which is complete nonsense. "Legacy file-open processing" isn't a real configurable option in Paint and this seems to suggest that enabling it is some sort of mitigation. The resolution is simply to update Paint.

It mentions that it may rely on other services or security measures running- I wonder if there’s something like this hitting a firewall or av and then that calling out to paint to check file type or size out something like that?

The direct implication is that current generations of ms paint are a “service over the network.” Probably a theoretically possible RPC end point of svchost.exe

It still makes it sound like the problem really is the other service that is letting a remote connection invoke some part of MS paint.

But why MS Paint? What functionality does it offer to another program to get called on specifically? And if this other service isn't calling on it specifically, what else can it be tricked into calling? And how many of those are also vulnerable to being stabbed in the back? The smaller interior holes are a problem, sure, but it seems like the CVE should be for the hull hole in that case.