3 ms·

> Is the fact your internal server 'gubbins.mydomain.com' exists, or even that it exists on 10.0.41.43 really much use? Pretty much this. What does it matter i

> Is the fact your internal server 'gubbins.mydomain.com' exists, or even that it exists on 10.0.41.43 really much use? Pretty much this. What does it matter if you know certain hostnames or internal IPs on my network? It's all firewalled anyway, and if it wasn't it would be trivial to find them out on your own...

Xylakant 6y ago
It may be of interest for attackers that have no visibility into your network and make cross site attacks against you easier. For example, if I know that your router is available at router.network.internal, I might just try and see if your browser is logged in and send you a link to a page that starts making requests against that interface. Enumerating network resources can certainly be done via other ways, but DNS is a particularly easy one.
- cassianoleal 6y ago
  Interesting but 192.168.0.1 or 192.168.1.1 would probably cover 80% of that use case. This is just security by obscurity. It doesn't add much if you already implement actual security in the form of firewalls, network segregation, etc.
  - Xylakant 6y ago
    I agree that it's certainly not a substitute for a proper security setup, but it definitely makes an attackers life easier - up to the point where it may get interesting to automate this. So as always, it's a tradeoff. Both options may be acceptable (and I've run a setup where I'd have internal names exposed on public DNS for years), but you need to be aware of the tradeoff to make that judgement.
iso1210 6y ago
I guess it could be useful for human level attacks, something like "Hi it's Bob down in IT, any chance you could reboot 'funkyserver123', it's on 172.18.12.5, for some reason I can't get in"
- cassianoleal 6y ago
  Why would I answer a request from Bob down in IT about my home network? Edit: I don't know why this is being downvoted. The OP is about a home k8s setup, so unless you live in some castle or palace I very much doubt there will be a Bob down in IT.
fomine3 6y ago
Possibly useful for SSRF attack but the matter is SSRF.

Xylakant 6y ago

It may be of interest for attackers that have no visibility into your network and make cross site attacks against you easier. For example, if I know that your router is available at router.network.internal, I might just try and see if your browser is logged in and send you a link to a page that starts making requests against that interface. Enumerating network resources can certainly be done via other ways, but DNS is a particularly easy one.

cassianoleal 6y ago
Interesting but 192.168.0.1 or 192.168.1.1 would probably cover 80% of that use case. This is just security by obscurity. It doesn't add much if you already implement actual security in the form of firewalls, network segregation, etc.
- Xylakant 6y ago
  I agree that it's certainly not a substitute for a proper security setup, but it definitely makes an attackers life easier - up to the point where it may get interesting to automate this. So as always, it's a tradeoff. Both options may be acceptable (and I've run a setup where I'd have internal names exposed on public DNS for years), but you need to be aware of the tradeoff to make that judgement.

iso1210 6y ago

I guess it could be useful for human level attacks, something like "Hi it's Bob down in IT, any chance you could reboot 'funkyserver123', it's on 172.18.12.5, for some reason I can't get in"

cassianoleal 6y ago
Why would I answer a request from Bob down in IT about my home network? Edit: I don't know why this is being downvoted. The OP is about a home k8s setup, so unless you live in some castle or palace I very much doubt there will be a Bob down in IT.

fomine3 6y ago

Possibly useful for SSRF attack but the matter is SSRF.