I just setup a minecraft server on an old laptop, but to make it acessible i needed to open up a port. Currently, these are the ufw rules i have. when my friends want to connect, i will have them find their public ip and ill whilelist only them. is this secure enough? thanks
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22/tcp ALLOW Anywhere Anywhere ALLOW my.pcs.local.ip`
also, minecraft is installed under a separate user, without root privlege
A port is not secure or insecure. The thing that can lead to security risks is the service that answers that port.
Use strong authentication and encryption on those services and keep them up to date.
as long you are only forwarding Minecraft’s 25565 port from your router to your server machine, it should be fine. Just make sure to keep Online mode on, use the whitelist, and get your plugins from trusted sources. Otherwise I wouldn’t worry too much.
I see others recommending VPN solutions like zerotier for your friends to connect to; I don’t personally feel like this is necessary, and (in my experience), making your friends do more technical setup than just connecting to the server is often a big turn-off.
Bonus: If you ever take a peek at your server logs while it’s running (and exposed to the Internet, if you avoid said VPN solutions), you might notice a lot of weird connections from IPs and usernames you don’t recognize. These are server scanners and threat scanners that look for vulnerable servers to connect to and exploit. This is normal and you’ll be fine as long as you keep that whitelist and stay up-to-date on developments in the server admin space.
if I were you, I would do IP whitelisting at the firewall instead of or besides the Minecraft server
This might also become a hassle since basically all residential connections (likely of OPs friends) have dynamic IPs - if someone wants to join while OP is away, but their IP has changed since their last connection, now they have to wait on OP to update the firewall rules.
Apart from getting your MSA token stolen, there’s not really much that can get around server login (yet). All online-mode logins pass through Microsoft (part of the reason why Xbox service outages seem to affect Minecraft so much).
If your friends all individually seem to stay within some certain IP ranges (ex, first handful digits always stay the same, 12.34.56.xx), then I’d say go ahead with whitelisting them fully (ex, 12.34.56.xx --> 12.34.56.0/24, CIDR notation). If they jump around unpredictability, I would stick with the username-based whitelisting and online-mode-only.
maybe a wireguard network is the way to go then, of course without being configured as the default destination for everything. there IPs are always fixed, but at that point you don’t even need a firewall
More effort than I would consider. I’d just allow all traffic incoming on that port. I’d only consider whitelist if someone was giving me grief. Even then that would be after blacklisting an IP wasn’t solving my problem.
Port 22 is the default SSH port and it receives a TON of malicious traffic any time it’s open to the whole internet. 20 years ago I saw a newly installed server with a weak root password get infected by an IP address in China less than an hour after being connected to the open internet.
With all the bots out there these days it would probably take a lot less time if we ran the same experiment again.
Ha. That’s my bad. I didn’t even read the firewall rules listing 22/SSH. I agree on not opening 22 to the world. It just invites bots throwing passwords at it.
I just read Minecraft in the original post which from reading runs from 25565 which I wouldn’t worry about. If OP needs 22 for admission I’d either whitelist it or use a VPN/Tailscale.
25565 also gets a decent amount of malicious traffic because of Minecraft though. I’d recommend switching the port to something different at the very least. When I hosted a server for the first time on 25565 my router pretty immediately gave me warnings about attempted network traffic coming from Europe/Asia when I (and everyone I gave the IP to) live in the US.
Why is port 22 open? Is this on your router as well or just the server?
This is SSH, which you should pretty much never have open (to the internet! Local is fine) MC is by default 25565. You will have every bot on the internet probing that port.
ssh is local only. so I should change all ports from default then huh
Your ssh rule says it’s from anywhere. You want to change port 22 to 25565, and run /op username on your Minecraft server to whitelist your friends. Make sure your whitelist flag is turned on with your server config.
Instead of allowing traffic over your port from anywhere, you can specify your friend’s external IP.
You can test it out by running ‘telnet <ip> <port>’ to check if the port is open. This is best done from another network.
Having SSH open to the internet is normal. Don’t use password authentication with weak passwords.
For public facing only use key based authentication. Passwords have too much risk associated for public facing ssh
Normal for who? I wouldn’t expose SSH on 22 to the internet unless you have someone whose full time job is monitoring it for security and keeping it up to date. There are a whole lotta downsides and virtually no upsides given that more secure alternatives have almost zero overhead.
Shodan reports that 35,780,216 hosts have SSH exposed to the internet.
Moving SSH to ports other than 22 is not security. The bots trying port 22 on random addresses with random passwords don’t have a chance of getting in unless you’re using password authentication with weak passwords or your SSH is very old.
SSH security updates are very infrequent and it takes practically no effort to keep SSH up to date. If you’re using a stable distribution, just enable automatic security updates.
Moving to another port isn’t a bad idea though. It gives you cleaner logs which is nice.
To be fair, if something is open by default or very easy to enable without informing about the risks, tons of people will have it exposed without thinking.
It isn’t that “tons of people do it so it is normal and perfectly fine” but more “people don’t realize.” It also uses some nontrivial amount of resources to process and block those attempts, even if they never have a chance of getting in.
There is yet a reason I can find to have it forwarded for home use. Need to ssh into a machine to fix it? VPN.
There are plenty of secure web-based tools to manage your server without a VPN also.
A large percentage of those hosts with SSH enabled are cloud machines because it’s standard for cloud machines to be only accessible by SSH by default. I’ve never seen a serious security guide that says to set up a VPN and move SSH behind the VPN, although some cloud instances are inherently like this because they’re on a virtual private network managed by the hosting provider for other reasons.
SSH is much simpler and more universal than a VPN. You can often use SSH port forwarding to access services without configuring a VPN. Recommending everyone to set up a VPN for everything makes networking and remote access much more complicated for new users.
OK that is fair, though that is not self hosted…
VPS machines are a completely different beast than self hosting. But I guess I only said home use, not specifically self-hosting though we are in a self-hosted community. There are 1000 guides for setting up a VPN on your home network.
Not for people who are asking questions about port forwarding
yeah no I should have considered that. didn’t lick the most secure password. will change when I get home
Don’t use passwords for public SSH in the first place. Disable password authentication and use pubkeys.
And disable ssh to root. Hell, just disable root login altogether and use sudo.
