In the past two weeks I set up a new VPS, and I run a small experiment. I share the results for those who are curious.
Consider that this is a backup server only, meaning that there is no outgoing traffic unless a backup is actually to be recovered, or as we will see, because of sshd.
I initially left the standard “port 22 open to the world” for 4-5 days, I then moved sshd to a different port (still open to the whole world), and finally I closed everything and turned on tailscale. You find a visualization of the resulting egress traffic in the image. Different colors are different areas of the world. Ignore the orange spikes which were my own ssh connections to set up stuff.
Main points:
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there were about 10 Mb of egress per day due just to sshd answering to scanners. Not to mention the cluttering of access logs.
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moving to a non standard port is reasonably sufficient to avoid traffic and log cluttering even without IP restrictions
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Tailscale causes a bit of traffic, negligible of course, but continuous.
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Public key auth, and fail2ban on an extremely strict mode with scaling bantime works well enough for me to leave 22 open.
Fail2ban will ban people for even checking if the port is open.
Honest question, is there a good default config available somewhere or is what
apt install fail2bandoes good to go? All the tutorials I’ve found have left it to the reader to configure their own rules.Honestly the default config is good enough to prevent brute force attacks on ssh. Just installing it and forgetting about it is a definite option.
I think the default block time is 10 minutes after 5 failed login attempts in 10 minutes. Not enough to ever be in your way but enough to fustrate any automated attacks. And it’s got default config for a ton of services by default. Check your /etc/fail2ban/jail.conf for an overview.
I see that a recidive filter that bans repeat offenders for a week after 10 fail2ban bans in one day is also default now. So I’d say that the results are perfect unless you have some exotic or own service you need fail2ban for.
Yeah fail2ban has worked great for me
If Fail2Ban is so important, why the h*** does it not come installed and enabled as standard?!
Security is the number-1 priority for any OS, and yet stock SSHD apparently does not have Fail2Ban-level security built in. My conclusion is that Fail2Ban cannot therefore be that vital.
I’ll take that tiny amount of traffic telling scanners there’s no password auth over having to remember port settings for ssh, scp and rsync any day.
For me it’s not about the traffic, more the log spam.
Generally I’ll have :22 enabled internally, and anything non-standard is defined in
~/.ssh/configand shared out so I don’t have to remember things.Fair point. These logs are only useless chatter anyway for everyone with proper key auth.
vim ~/.ssh/configdeleted by creator
Just do it properly and configure sshd securely. When you have a machine exposed to the internet, you should expect it to be attacked. If you really want to give the finger to bots, run endlessh on port 22 and keep sshd on a non-standard port. Stay safe.
endlessh
Lmao thanks for this
I opened a raw text channel on the Telnet port for a personal game engine project and someone tried to enable commands and do some shady stuff. Unfortunately for them, that’s not a valid chess move.
10mb is pretty much nothing. May as well just use Fail2Ban.
Now try IPv6 only :P
Next time
If you do want to open 22, and there are plenty of good reasons to want to, just implement something called port knocking and you can do it safely.
Note with this you still need good authentication. That means no passwords, key based auth only.
I have read elsewhere that port knocking is just security through obscurity and isn’t worth considering. I found it when searching for ways to set it up and that put me off.
The best reason is reducing attack surface. It’s such an easy thing to do. I don’t know why people still expose services they don’t need to.
Moving the port doesn’t reduce attack surface. It’s the same amount of surface.
Tailscale is a bit controversial because it requires a 3rd party to validate connections, a 3rd party that is a large target for threat actors, and is reliant on profitability to stay online.
I would recommend a client VPN like wireguard, or SSH being validated using signed keys against a certificate authority your control, with fail2ban.
I don’t know if it was mentioned already but how could I check if my ports are under “attack”? OPs graphic looks really nice
Hi, to check attacks you should look at the logs. In this case auth.log. Being attacked on port 22 is not surprising neither really troublesome if you connect via key pair.
My graph was showing egress traffic, on any kind of server the traffic due to these attacks would have been invisible but on a backup server which has (hopefully) only ingress you can clearly see the volume of connections from attackers from bytes teansmitted
And yet it is more likely that tailscale get owned since the reward is much higher. I take my chances with my secured openssh server at port 22 vs a 3rd party company who controlls the access.
Just setup a wireguard system that’s pretty bulletproof
So is SSH
Wireguard doesn’t respond but I agree open-ssh is pretty solid. Can’t speak for any of the other ssh implementations. It can also be poorly configured. Like you could use a password
The benefit of Wireguard is that if you screw it up, it just won’t work. It basically enforces security.
Well, unless you tried to use the original PFSense module.
You really shouldn’t have something kike SSHD open to the world, that’s just an unnecessary atrack surface. Instead, run a VPN on the server (or even one for a network if you have several servers on one subnet), connect to that then ssh to your server. The advantage is that a well setup VPN simply won’t respond to an invalid connection, and to an attacker, looks just like the firewall dropping the packet. Wireguard is good for this, and easy to configure. OpenVPN is pretty solid too.
You say this and are downvoted.
While we are coming off the tail of Def Con where there where a plethora or small talks and live examples of taking advantage and abusing just this.
Just trying to parse your comment, I assume your first “this” and second “this” are referring to different things, right?
I don’t understand your comment, what you are saying. Could you elaborate a bit, please? I’m interested why it’s a bad idea what previous comment suggested.
Of course I can dig into DefCon videos and probably would do if needed, but perhaps you know what exactly the issue is
The first this means the comment he answered to and the second one means ssh being used as an attack surface, being described in defCon talks
Whys this a problem disable password auth and wish em good luck lol.
What software did you use you monitor this? I am newish to self hosting and would like to secure my connection better.
Sorry, it’s the built-in console of Google Cloud. But there are so many monitoring solution around that you can probably find one of your liking. Look on awesome-selfhosted for “monitoring”
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What’s the Enthusiasm About?
Hello there! Are you familiar with Go High Level? If not, let’s break it down. Imagine managing multiple apps for marketing. Sounds busy. That’s where Go High Level comes in. It’s like that friend who has a solution for everything. Whether you are working on creating an outstanding sales funnel or sending out an email campaign, this platform has your back. The best part? They let you test drive everything with a 14-day free trial. It’s like trying out a new car but for your business. And if you ever need assistance, their support team is just a click away. Pretty exciting, huh? -
So, How Much Does It Cost?
Alright, let’s talk about the financial side. Go High Level offers 3 main plans. The Agency Starter Plan is perfect if you’re just starting or have a small business. It’s loaded with all the essential tools, and it’s quite cost-effective. But if you’re looking to scale up, the Agency Unlimited Plan is your best choice. It’s like the VIP pass at a concert, giving you access to everything without any limitations. Not sure about committing? Remember that 14-day free trial I mentioned? It’s a great way to give it a try without any obligations. Lastly, they offer a Pro plan that includes “SaaS mode,” where you can white label the product under your brand. Fantastic! -
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In a world full of sophisticated digital tools, Go High Level is like that all-in-one Swiss Army knife. There’s no need to switch between apps because it has everything under one roof. Whether you’re a newcomer or an experienced marketer, it’s super user-friendly. It’s not just about launching impressive campaigns; they ensure you understand their performance with top-notch analytics. There’s even a white-label feature for marketing agencies, so you can add your brand and impress your clients.
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