Help me harden my home server

miau@lemmy.sdf.org to Selfhosted@lemmy.world – 115 points –

I currently have a home server which I use a lot and has a few important things in it, so I kindly ask help making this setup safer.

I have an openWRT router on my home network with firewall active. The only open ports are 443 (for all my services) and 853 (for DoT).

I am behind NAT, but I have ipv6, so I use a domain to point to my ipv6, which is how I access my serves when I am not on lan and share stuff with friends.

On port 443 I have nginx acting as a reverse proxy to all my services, and on port 853 I have adguardhome. I use a letsencrypt certificate with this proxy.

Both nginx, adguardhome and almost all of my services are running in containers. I use rootless podman for containers. My network driver is pasta, and no container has "--net host", although the containers can access host services because they have the option "--map-guest-addr" set, so I don't know if this is any safer then "--net host".

I have two means of accessing the server via ssh, either password+2fa or ssh key, but ssh port is lan only so I believe this is fine.

My main concern is, I have a lot of personal data on this server, some things that I access only locally, such as family photos and docs (these are literally not acessible over wan and I wouldnt want them to be), and some less critical things which are indeed acessible externally, such as my calendars and tasks (using caldav and baikal), for exemple.

I run daily encrypted backups into OneDrive using restic+backrest, so if the server where to die I believe this would be fine. But I wouldnt want anyone to actually get access to that data. Although I believe more likely than not an invader would be more interested in running cryptominers or something like that.

I am not concerned about dos attacks, because I don't think I am a worthy target and even if it were to happen I can wait a few hours to turn the server back on.

I have heard a lot about wireguard - but I don't really understand how it adds security. I would basically change the ports I open. Or am I missing something?

So I was hoping we could talk about ways to improve my servers security.

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Admittedly I'm paranoid, but I'd be looking to:

  1. Isolate your personal data from any web facing servers as much as possible. I break my own rule here with Immich, but I also...
  2. Use a Cloudflare tunnel instead of opening ports on your router directly. This gets your IP address out of public record.
  3. Use Cloudflare's WAF features to limit ingress to trusted countries at a minimum.
  4. If you can get your head around it, lock things down more with features like Cloudflare device authentication.
  5. Especially if you don't do step 4: Integrate Crowdsec into your Nginx setup to block probes, known bot IPs, and common attack vectors.

All of the above is free, but past step 2 can be difficult to setup. The peace of mind once it is, however, is worth it to me.

Thanks for your reply!

Suggestion 1 definetely does make a lot of sense and I will be doing exactly that asap. Its something I didnt think through before but that would make me much more in peace.

Suggestions 2-4 sound very reasonable, I have indeed searched for a way to self host a waf but didnt find much info. My only only concern with your points is... Cloudflare. From my understanding that would indeed add a lot of security to the whole setup but they would then be able to see everything going through my network, is that right?

Yes and no? It's not quite as black and white as that though. Yes, they can technically decrypt anything that's been encrypted with a cert that they've issued. But they can't see through any additional encryption layers applied to that traffic (eg. encrypted password vault blobs) or see any traffic on your LAN that's not specifically passing through the tunnel to or from the outside.

Cloudflare is a massive CDN provider, trusted to do exactly this sort of thing with the private data of equally massive companies, and they're compliant with GDPR and other such regulations. Ultimately, the likelihood that they give the slightest jot about what passes through your tunnel as an individual user is minute, but whether you're comfortable with them handling your data is something only you can decide.

There's a decent question and answer about the same thing here: https://community.cloudflare.com/t/what-data-does-cloudflare-actually-see/28660

Yes absolutely. For work most of my clients use cloudflare's different services so I understand they have credibility.

For me though, part of the reason I self host is to get away from some big tech companies' grasp. But I understand I am a bit extreme at times.

So thanks for opening my mind and pointing me to that very interesting discussion, as well as for sharing your setup, it sure seems to be very sound security wise.

Sounds exactly like my setup for the last 5 years, minus NGINX (don't need it with Cloidflared since each service is it's own Proxmos Container and use their own exclusive tunnels).

  1. Guess what, all IP addresses are known. There is no secret behind them. And you can scan all IPv4 addreses for ports in a few seconds at most.
  2. So some countries are more dangerous than others? Secure your network and service and keep them up to date, then you do not have to rely on nonsense geoblocking.
  3. Known bots are also no issue most of the time. They are just bots. They usually target a decade old Vulnerabilities and try out default passwords. If you follow my advice on 3. this is a non issue
  1. Sure but there's no reason to openly advertise that yours has open services behind it.
  2. Absolutely. There are countries that I'm never going to travel there so why would I need to allow access to my stuff from there? If you think it's nonsense then don't use it, but you do you and I'll do me.
  3. See point 3.

We all need to decide for ourselves what we're comfortable with and what we're not and then implement appropriate measures to suit. I'm not sure why you're arguing with me over how I setup my own services for my own use.

Yes i do i and you do you. But advertising those things as security measures while not adding any real security is just snake oil and can result in neglecting real security measures.

As i said, the whole internet can be port scanned within seconds, so your services will be discovered, what is the risk you assume to have when your IP address is known and the fact that you host a service with it? The service has the same vulnerabilities if it is hosted via cloudflare tunnels or directly via port forwarding on the router. So you assume that your router is not secure? Then unplug it, cause it is already connected to the router.

Geoblocking is useless for any threat actor. You can get access to VPN services or a VPS for very very very little money.