I’d suggest that running a vulnerable production service is asking for trouble!

My web logs are full of automated scanners. Once when I ran a vulnerable version of Wordpress it got discovered and pwned very quickly. No need to enter the URL in any website ;)

This just seems like a mailing list for CVE alerts for popular software. If you put in HN, it'll say that it failed to detect the stack, and then ask you to choose your software and then enter your email to receive alerts.

It's kind of clever marketing, giving people a sense that they're going to get a security audit in exchange for an email address.

The first URL I entered (coop.co.uk) was actually pretty awesome, it detected Varnish and showed a critical CVE from last week. That’s cool.

I hope that if you subscribe, the site regularly rescans your stack and realised if it’s changed. Otherwise it’s just a mailing list subscription that becomes out of date and therefore not useful.

Anyone can (and people are) just scan the internet for hosts on port 80/443 and unless your site uses virtual hosts and has no HTTPS certificates issued to one of your domains, it's going to be discovered and probed exactly like this site does anyways. The difference is real adversaries are doing it without you knowing.

This is the textbook definition of security by obscurity.

It's not even that. There's no obscurity here. This is security by pretending.

Security by head in the sand. Can't be any vulnerablities if I don't know about them.

Then somebody else is going to do it for you.