Let’s assume you’re right and the crypto itself is sound. I agree that is likely and doubt any TLAs have a significant mathematical edge. Does the NSA just stop there and call it a day? No, of course they write Stuxnet. They attack everything else.
Keep in mind that openbsd has a tiny base install, so it's not exactly surprising that there aren't a lot of remote exploits. Nothing's listening by default, so why would there be?
By the time you set up OpenBSD to do anything, that's gonna change.
What well known piece of software isn’t broken?