BonkTheAnnoyedJan 11

How are people discovering random subdomains on my server?

https://lemmy.blahaj.zone/post/36861104

Blåhaj Lemmy - Choose Your Interface

Show threadBombasticJan 11
Inb4 some lucky dude just ran sublist3r or wfuzz on your subdomain and got a hit
Show threadBonkTheAnnoyedJan 11
I mean, it could be… I’ll try it with a 128 char base 52 name and see what happens
Show threadKeelhaul
Have you also tried making a subdomain and not making any requests to it yourself? So no browser access or other DNS resolution requests for the new subdomain. That should rule out some of the other possible causes suggested in the other comments.
Jan 11 at 10:18amWeb
Show thread Morphit Jan 12

Dang, it could be the upstream DNS server passing along client queries. Maybe the ISP?

In that case not even curl would be safe unless you could ensure all queries only resolve on your gear. Either use a host file entry or local DNS server.