I have my services proxied through nginx and behind cloudflares free tier. That way I don’t have to worry about my IP getting exposed and opening myself up to DDOS/DOS attacks, which is a genuine threat if you do things that piss people off (I’m an admin on a popular minecraft server).

If you port forward to your Pi, only your Pi will be exposed. But, if your Pi gets pwned, it can in turn attack anything next to it. Safest is to isolate the Pi on it’s own subnet or a DMZ if your router has the functionality.

Of note, many home ISPs block standard server ports like 80 and 443. You might need to use non standard ports like 8080 and 8443

You’ll be ok as long as whatever software you’re running that is listening to 80 and 443 never has an exploitable vulnerability, if it does… you may be in trouble depending on the vulnerability.

Or be careful of the service on the other side of your (I assume) reverse proxy, should it have a vulnerability you may still be in trouble depending on the setup of the reverse proxy and what it’s config is.

I have no idea but am interested in answers.

I’ve only exposed ports briefly for testing and got scared.

I feel a little calmer using tailscale the past few months but still feels like putting a lot of faith in someone I don’t really know I can trust.

The port forward only forwards to a single device so you aren’t exposing your PC (directly anyway). Sounds like you have the pi good and secured but if you wanted to add another layer you could segment it out into a DMZ or its own VLAN. That way if something did happen with it an attacker couldn’t move laterally inside your network.

Realistically though you’re in good shape.

You should be fine. If you are using port forwarding the inbound traffic on that port should be sent only to the system you have designated. The only way that changes is if the system (rpi in this case) is operating as a reverse proxy. Even then net side should only see the proxy.

The biggest vulnerability would be the system that you are forwarding to, and if that system is a reverse proxy whatever the backend systems are. Make sure everything is fully updated/patched and that you trust the services that you are running and you should be good.

My only comment on your setup would be to make sure you fully understand what you are doing and more importantly, why. Cargo Culting is a bad way to admin. Good questions like yours are a good way to start.

You could put the pi on its own subnet. That way if it’s hacked, the rest of the network is protected. Just make sure your router admin interface doesn’t answer on that subnet.

I did this for some time. But now I don’t want any ports open at home.

That’s why I have a rented VPS that runs Traefik (a reverse proxy). This VPS has a VPN connection to my home net and is behind Cloudflare DNS. This is how I can safely expose services (even in my home net) to the Internet without forwarding any ports.

Of course those services need to have some kind of authentication.

No

It should be safe, as it just exposes the Raspberry Pi. Make sure you’ve configured fail2ban to also watch the logs of all your webapps and ban people that try to brute force them (for example, if you host your own Vaultwarden instance, fail2ban should be configured to watch the Vaultwarden log for authentication failures).

For web apps that only you need to access (i.e. they do not have to be exposed publicly), consider using a VPN to access them remotely, instead of exposing the apps publicly. Wireguard and Tailscale work well for this. Tailscale is built on top of Wireguard and makes it very easy to get up and running.

You are probably going to be ok unless someone really wants to hack you. The LastPass hack that exposed passwords of millions of people started from an open port in the home network of one of their engineers.

If you want to be somewhat safer, you could try something like the cloudflare tunnel thing to proxy your home network through their server.

Forwarding a port only forwards traffic to the device you specify. Be prepared for plenty of port scans though. If you have internal system email set up your Fail2Ban will be sending you daily messages. I get 5 or 6 a day from automated port scans triggering Fail2Ban.

I would suggest signing up for a free Cloudflare account and setting up any DNS for your Pi through there, using the Cache feature.

Once that is done, setup an automated script that will pull down Cloudflare IPs into a file (you can use a cronjob to run this daily):

#!/bin/bash

set -e

cf_ips() {
  echo "# https://www.cloudflare.com/ips"

  for type in v4 v6; do
    echo "# IP$type"
    curl -sL "https://www.cloudflare.com/ips-$type/" | sed "s|^|allow |g" | sed "s|\$|;|g"
    echo
  done

  echo "# Generated at $(LC_ALL=C date)"
}

cf_ips > allow-cloudflare.conf
(cf_ips && echo "deny all; # deny all remaining ips") > allow-cloudflare-only.conf

Then in your web server config to only accept connections from Cloudflare IPs:

server {
	listen 80 default_server;
	listen [::]:80 default_server;
	server_name example.com;
        root /var/www/html;

	include /etc/nginx/allow-cloudflare-only.conf;
}

I prefer this method over UFW/iptables block as it allows you to control the IP block per web config, so if needed, you can make exceptions by not adding the include /etc/nginx/allow-cloudflare-only.conf; into that specific site’s conf file.

You could accidentally expose another device if the Pi and other devices all get dynamic IPs in your local network, you might want to set a fixed IP outside of the DHCP Server’s range for dynamically assigned addresses for the Pi.

If you run your webserver in a sandbox, that adds an extra layer of security. Something like docker, or a classic setup where you have a special user account with limited access, is good. So if the server gets owned, the damage is still contained

Random webservers online are still often attacked, so disabling all password based access is helpful. You may have to occasionally look at the connections log and ip ban some attempts