I was hacked one single time in my entire 25 year long career. Someone hacked a bind server I was running and installed some sort of bot node. That was in the 90’ies.
That feels weird somehow. I highly doubt PiHole is the culprit. If you're only using it internal to your LAN for DNS there is no way someone from outside can touch it. You most likely have other, bigger problems with your network (perhaps the WiFi password was discovered by someone, or you're exposing other vulnerable services to the web directly).
Agreed, I managed to achieve this by port forwarding port 53 in my router settings. This allows hackers to enlist you in their DNS amplification attacks so please never do this.
Do you have a good guide for this? I sort of grok that the Pi (server) setup is different from the devices (clients) that will use it, but it’s always good to check assumptions.
I already run PiHole, but I might run this on a different box just to keep things simple.
Also, last I checked - port 51820 is reasonably well known, is it safe to use this default when forwarding traffic?
To be fair, that was probably due to something else than the DNS stack. For example, i assume the web interface downloads countless dependencies from a 3rd party repo (such as npmjs), any of which could have been victim of a hostile takeover.
DNS is nowadays very robust and secure, and if you have unattended-upgrades configured there's literally zero reason to be frightened by DNS.
