Perhaps this is a weird question I have, but I’ve been watching some technotim videos lately and he seems to have local dns addresses for local services. Perhaps I’ve got this wrong, but if not: how would you go over doing this?
I have a pterodactyl dashboard, which I access locally using the machines IP and the port, but it would be great to have a pterodactyl.example.com domain, which isn’t accessible from other networks, but does work on my own network. I also still want some services exposed to the internet, so I’m not sure if this would work.
But the attacker should know the internal and the external DNS. If the internal DNS doesn’t have any SSL certificate on its name, it’s impossible to discover.
By the way, I always suggest to reach services through VPN and use something like Cloudflare tunnel for services that must be public.
P.s. Shouldn’t public and private DNS be inverted in your curl example?
Nope, that curl command says ‘connect to the public ip of the server, and ask for this specific site by name, and ignore SSL errors’.
So it’ll make a request to the public IP for any site configured with that server name even if the DNS resolution for that name isn’t a public IP, and ignore the SSL error that happens when you try to do that.
If there’s a private site configured with that name on nginx and it’s configured without any ACLs, nginx will happily return the content of whatever is at the server name requested.
Like I said, it’s certainly an edge case that requires you to have knowledge of your target, but at the same time, how many people will just name their, as an example, vaultwarden install as vaultwarden.private.domain.com?
You could write a script that’ll recon through various permuatations of high-value targets and have it make a couple hundred curl attempts to come up with a nice clean list of reconned and possibly vulnerable targets.