As the title says, I want to know the most paranoid security measures you’ve implemented in your homelab. I can think of SDN solutions with firewalls covering every interface, ACLs, locked-down/hardened OSes etc but not much beyond that. I’m wondering how deep this paranoia can go (and maybe even go down my own route too!).
Thanks!
Nice try, attacker trying to get me to do their reconnaissance work for them. I’m on to you.
It would be funny if that were the case. I was just hoping to be a little more paranoid from you lot and maybe improve on the things I’ve thought about
Yeah, just having a little fun in the role of a paranoid admin. My setup isn’t worth mentioning since it fits my threat model (i.e. nobody gives a shit about my network, just don’t be the low hanging fruit) but I’m interested in other replies. Hope you get some useful responses here.
I’d love to play paranoid admin over my network. Thanks!
No, honestly I’m not an attacker, but your local bank. We just need your help to update our systems. Please provide us the following credentials to continue using our phish- *ugh* services.
Credit card number: _____________
CVV: ___
Expiration date: ______Spfff me, never Anyway please tell me more about your IP adress and your private keys.
My private key has a 3 in it
Ok my ip address is 192.168.3.200.
Im gonna hack u now
Hey its me your friend Aaron how are you. Hey i was just wandering, what is your credit card details again? just wandering
My most paranoid config is disabling Ipv4
That’s it. If someone wants to attack me, they will need to adopt IPv6!
Logcheck. It took ages to make sure innocent logs are ignored, but now I get an email as soon as anything non-routine happens on my servers. I get emails with logs from every update, every time I log in, etc. This has given me the most confidence that nothing unexpected is happening on my servers. Of course, one needs to make sure that the firewall is configured well, and that you use ssh keys etc., but logcheck is how I know I’m doing enough.
Very nice idea, and it’s quite simple too. Thanks
I’ve replaced reconnaissance commands (a handful of them found here: https://www.cybrary.it/blog/linux-commands-used-attackers) – whoami, uname, id, uptime, last, etc
With shell scripts which run the command but also send me a notification via pushover. I’m running several internet-facing services, and the moment those get run because someone is doing some sleuthing inside the machine, I get notified.
It doesn’t stop people getting in, I’ve set up other things for that – but on the off chance that there is some zero-day that I don’t know about yet, or they’ve traversed the network laterally somehow, the moment they run one of those commands, I know to kill-switch the entire thing.
The thing is, security is an on-going process. Leave any computer attached to the internet long enough and it’ll be gotten into. I don’t trust being able to know every method that can be used, so I use this as a backup.
That’s a very good idea. Something to think about, especially if you have open ports and are paranoid enough (aren’t we all? Hehe). Thanks
My security is fairly simplistic but I’m happy with it
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software protection
- fail2ban with low warning hold
- cert based login for ssh (no password Auth)
- Honeypot on all common port numbers, which if pinged leads to a permanent IP ban
- drop all firewall
- PSAD for intrusion/scanning protection (so many Russian scanners… lol)
- wireguard for VPN to access local virtual machines and resources
- external VPN with nordVPN for secure containers (yes I know nord is questionable I plan to swap when my sub runs out)
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physical protection
- luksCrypt on the sensitive Data/program Drive ( I know there’s some security concerns with luksCrypt bite me)
- grub and bios locked with password
- UPS set to auto notify on power outage
- router with keep alive warning system that pings my phone if the lab goes offline and provides fallback dns
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things I’ve thought about:
- a mock recovery partition entry that will nuke the Luks headers on entry (to prevent potential exploit getting through grub)
- removing super user access completely outside of local user access
Could you please elaborate how you do the honeypotting?
I just expanded the existing fail2ban config on the commonly used default ports such as 22, 21 Etc, any requests on those ports get sent into purgatory, so the ip gets blacklisted any connections from it hangs until it times out. It’s a super basic setup iptables logs whenever a request is not in the current firewall (last rule in the chain) and then fail2ban reads the log and handles the block. I don’t count it as part of the normal setup because they’re isolated Because the actual ports the service is on still have the normal rule set but the default port numbers are just an instant if there’s activity on it you’re gone
What honeypot are you using?
deleted by creator
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Really all I do is setup fail2ban on my very few external services, and then put all other access behind wireguard.
Logs are clean, I’m happy.
Standard and well-tested setup. Thanks for your reply!
- Custom Router/Firewall running OPNsense and the Sensei plugin
- Extensive DNS filtering through Pihole
- Redirecting all DNS requests to my Pihole through OPNsense
- My entire network is behind a multi hop VPN
- I don’t let any Windows systems connect to the internet, instead, I have a Linux server which is connected to the internet (through a VPN of course) and runs a browser, and I use X2go to access the browser which is running on the Linux server
Since you’re running x86 for your router, do you actively prevent ME from trying to connect to the Internet?
I am aware of the ME, but I can’t really do anything about it. Current ARM SBCs are not suitable for a router/firewall (at least in my experience). I’m not that concerned about it though.
OpenWRT isn’t half bad for usual “router stuff”, but advanced usage is a bit hard to do. Of course, that doesn’t eliminate the problem since ARM can have plenty of backdoors too
I know, I tried OpenWRT on a Pi, but the experience wasn’t great (at least not as a home router).
Using SPA firewall knocking (fwknop) to open ports to ssh in. I suppose if I was really paranoid, the most secure would be an air gap, but there’s only so much convenience I’ll give up for security.
I’m going to save your comment because it has opened up a new technique for network security that I had never thought of before. Thanks a bunch
I understand some of these words.
Only remote access by wireguard and ssh on non standard port with key based access.
Fail2ban bans after 1 attempt for a year. Tweaked the logs to ban on more strict patterns
Logs are encrypted and mailed off site daily
System updates over tor connecting to onion repos.
Nginx only has one exposed port 443 that is accessible by wireguard or lan. Certs are signed by letsencrypt. Paths are ip white listed to various lan or wireguard ips.
Only allow one program with sudo access requiring a password. Every other privelaged action requires switching to root user.
I dont allow devices I dont admin on the network so they go on their own subnet. This is guests phones and their windows laptops.
Linux only on the main network.
I also make sure to backup often.
System updates over tor connecting to onion repos.
How does this help, assuming your DNS isn’t being spoofed?
Please see my reply below with links.
Thanks, never thought of that before. I’ll certainly try it, great way to help the network!
Fail2ban bans after 1 attempt for a year.
Fail2ban yes; one year, however, is IMO a bit excessive.
Most ISP IP assignments do tend to linger - even with DHCP the same IP will be re-assigned to the same gateway router for quite a number of sequential times - but most IPs do eventually change within a few months. I personally use 3 months as a happy medium for any blacklist I run. Most dynamic IPs don’t last this long, almost all attackers will rotate through IPs pretty quickly anyhow, and if you run a public service (website, etc.), blocking for an entire year may inadvertently catch legitimate visitors.
Plus, you also have to consider the load such a large blocklist will have on your system, if most entries no longer represent legitimate threat actors, you’ll only bog down your system by keeping them in there.
Fail2ban can be configured to allow initial issues to cycle back out quicker, while blocking known repeat offenders for a much longer time period. This is useful in keeping block lists shorter and less resource-intensive to parse.
My block list is very small actually due to the non standard ssh port. Everything else goes through wireguard.
If it was open to the public then yes I’d have to reconsider the ban length.
That makes a lot more sense for your setup, then.
I’m not super paranoid about security, but I do try to have a few good practices to make sure that it takes more than a bot scanning for /admin.php to find a way in.
- Anything with SSH access uses key-based auth with password auth disabled. First thing I do when spinning up a new machine
- Almost nothing is exposed directly to the Internet. I have wireguard set up on all my devices for remote access and also for extra security on public networks
- Anyone who comes to visit gets put on the “guest” network, which is a separate subnet that can’t see or talk to anything on the main network
- For any service that supports creating multiple logins, I make sure I have a separate admin user with elevated permissions, and then create a non-privileged user that I sign in on other devices with
- Every web-based service is only accessible with a FQDN which auto-redirects to HTTPS and has an actual certificate signed by a trusted CA. This is probably the most “paranoid” thing I do, because of the aforementioned not being accessible on the Internet, but it makes me happy to see the little lock symbol on my browser without having to fiddle around with trusting a self-signed cert.
Every web-based service is only accessible with a FQDN which auto-redirects to HTTPS and has an actual certificate signed by a trusted CA
I’m assuming this is in your internal network. The problem with this is that communication from the client to the reverse-proxy (unless you’re running a reverse-proxy sandboxed with each application/are directly decrypting traffic at the base of your application) is encrypted, but the traffic from the server to the reverse-proxy is not.
Definitely a consideration. In my case, the vast majority of my services are running in docker on a single host box, including the reverse proxy itself (Traefik). That unencrypted traffic never goes out over a wire, so for now I’m not concerned.
Bonus points for creating lots and lots of networks grouping the databases together with only their respective containers.
ip ais a huge mess.
- full disk encryption on everything except the router (no point in encrypting the router)
- the server doesn’t have a display connected for obvious reasons, so I’m manually unlocking it via ssh on each boot
- obviously, the SSH keys are different, so the server has a different IP in initrd. That said, I still don’t have any protection against malicious modification of initrd or UEFI
- the server doesn’t have a display connected for obvious reasons, so I’m manually unlocking it via ssh on each boot
- the server scans all new SSL certificates in realtime using certspotter and notifies me of any new certificates issued for my domains that it doesn’t know about (I use Cloudflare so it triggers relatively often, but I still do checks on who the issuer is)
- firewall blocks outgoing 25 so nobody can impersonate my mailserver
Thanks, I’d like to know more about your public-facing setup using cloudflare
there’s not much to know about it, I use Cloudflare simply because its routing is better than direct IP connections for many places on Earth. I can’t fully use Cloudflare anyway because I host many non-web services.
You might be interested in setting up network bound encryption via Clevis and Tang. I use a hidden pi zero in my house acting as a Tang server. It’s great being able to reboot any of my encrypted servers without having to manually unlock disks.
Do you recommend any resources about this? I’d be interested in learning how to implement this.
I’m using the recently merged Clevis module for NixOS. There was a recent talk at FOSDEM about it.
I know about it, but it kinda defeats the purpose (the purpose being police raid protection)
- full disk encryption on everything except the router (no point in encrypting the router)
NAT 🥴
I’ve got systems that can detect suspicious activities in the net, which result in a shutdown of the router. And not like “could you please shut down” but a hard power off type of shutdown.
Oh, you have a setup that signals to your power source to shut off internet when it detects an anomaly on the internet? That’s quite specific, and I’m having trouble trying to understand the use-case here, but it’s definitely included in the paranoid-list. Thanks!
Following for my own edification!
Hope I get a lot of good answers!
