Random (no pun intended) thought after reading this: how much of the supposedly secure HTTPS/TLS traffic is terminated by hardware load balancers and such that aren't really open and might have similar vulnerabilities?
Many appliance vendors have terrible self-made TLS stacks. There's a bunch of vendors whose names come up again and again when talking about stupid TLS bugs and vulnerabilities. Cisco, F5, Cavium, A10, Citrix, Fortinet are names that come to mind. And it's not only a problem for security, it's also a huge compatibility problem, as they tend to violate the protocol in ways that makes deploying new features and versions hard.
I've once given a talk where I tried to highlight this: https://www.youtube.com/watch?v=w3Sn5kMPzVA (slides unfortunately not in the video, but here https://int21.de/slides/auscert-tls/ )
And many sites use CDNs or cloud services for connection termination. Cloudflare and Amazon are surely on top of these things.