this post was submitted on 10 Feb 2025
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    Background: 15 years of experience in software and apparently spoiled because it was already set up correctly.

    Been practicing doing my own servers, published a test site and 24 hours later, root was compromised.

    Rolled back to the backup before I made it public and now I have a security checklist.

    top 50 comments
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    [–] potentiallynotfelix@lemmy.fish 1 points 28 minutes ago

    Weird. My last setup had a NAT with a few VMs hosting a few different services. For example, Jellyfin, a web server, and novnc/vm. That turned out perfectly fine and it was exposed to the web. You must have had a vulnerable version of whatever web host you were using, or maybe if you had SSH open without rate limits.

    [–] Thcdenton@lemmy.world 7 points 3 hours ago

    I usually just follow this

    [–] sommerset@thelemmy.club 20 points 6 hours ago (2 children)

    I'm confused. I never disable root user and never got hacked.

    Is the issue that the app is coded in a shitty way maybe ?

    [–] Xanza@lemm.ee 12 points 5 hours ago (2 children)

    You can't really disable the root user. You can make it so they can't login remotely, which is highly suggested.

    [–] possiblylinux127@lemmy.zip 7 points 4 hours ago (1 children)
    sudo passwd -l root
    

    This disables the root user

    [–] Xanza@lemm.ee 1 points 1 hour ago (1 children)

    There's no real advantage to disable the root user, and I really don't recommend it. You can disable SSH root login, and as long as you ensure root has a secure password that's different than your own account your system is just as safe with the added advantage of having the root account incase something happens.

    [–] possiblylinux127@lemmy.zip 1 points 45 minutes ago

    That wouldn't be defense in depth. You want to limit anything that's not necessary as it can become a source of attack. There is no reason root should be enabled.

    [–] MehBlah@lemmy.world 1 points 4 hours ago

    Another thing you can do under certain circumstances which I'm sure someone on here will point out is depreciated is use TCP Wrappers. If you are only connecting to ssh from known IP addresses or IP address ranges then you can effectively block the rest of the world from accessing you. I used a combination of ipset list, fail2ban and tcp wrappers along with my firewall which like is also something old called iptables-persistent. I've also moved my ssh port up high and created several other fake ports that keep anyone port scanning my IP guessing.

    These days I have all ports closed except for my wireguard port and access all of my hosted services through it.

    [–] cley_faye@lemmy.world 3 points 5 hours ago

    You can't really disable it anyway.

    Hardening is mostly prevent root login from outside in case every other layer of authentication and access control broke, do not allow regular user to su/sudo into it for free, and have a tight grip on anything that's executable and have a setuid bit set. I did not install a system from scratch in a long time but I believe this would be the default on most things that are not geared toward end-user devices, too.

    [–] IDKWhatUsernametoPutHereLolol@lemmy.dbzer0.com 3 points 4 hours ago (1 children)
    [–] conc@lemmy.ml 1 points 3 hours ago
    [–] MonkderVierte@lemmy.ml 3 points 7 hours ago

    Yeah, about this; any ssh server that can be run as user and doesn't do shenanigans like switching user?

    [–] recklessengagement@lemmy.world 24 points 12 hours ago

    This sounds like something everyone should go through at least once, to underscore the importance of hardening that can be easily taken for granted

    [–] ohshit604@sh.itjust.works 21 points 13 hours ago* (last edited 12 hours ago) (1 children)

    I can’t even figure out how to expose my services to the internet, honestly it’s probably for the best Wireguard gets the job done in the end.

    [–] Valmond@lemmy.world 3 points 9 hours ago (2 children)

    I'm interested, how do you expose your services (on your PC I assume) to the internet through wireguard? Is it theough some VPN?

    [–] Zanathos@lemmy.world 5 points 7 hours ago (2 children)

    Wireguard IS a VPN. He has somehow through his challenges of exposing services to the internet, exposed wireguard from his home to the internet for him to connect to. Then he can connect to his internal services from there.

    It's honestly the best option and how I operate as well. I only have a handful of items exposed and even those flow through a DMZ proxy before hitting their destination servers.

    [–] Valmond@lemmy.world 2 points 5 hours ago* (last edited 5 hours ago)

    Oh, I thought it was a protocol for virtual networks, that merely VPNs used. The more you know!

    Edit: spelled out VPN πŸ˜…

    [–] ohshit604@sh.itjust.works 2 points 6 hours ago

    VPN’s are neat, besides the fact they’re capable of masking your IP & DNS they’re also capable of providing resources to devices outside a network.

    A good example is the server at my work is only accessible on my works network, to access the server remotely without exposing it directly to the internet would be to use a VPN tunnel.

    [–] nonentity@sh.itjust.works 21 points 14 hours ago (4 children)

    Permitting inbound SSH attempts, but disallowing actual logins, is an effective strategy to identify compromised hosts in real-time.

    The origin address of any login attempt is betraying it shouldn’t be trusted, and be fed into tarpits and block lists.

    [–] varnia@lemm.ee 8 points 7 hours ago

    Endlessh and fail2ban are great to setup a ssh honeypot. There even is a Prometheus exporter version for some nice stats

    Just expose endlessh on your public port 22 and if needed, configure your actual ssh on a different port. But generally: avoid exposing ssh if you don't actually need it or at least disable root login and disable password authentication completely.

    https://github.com/skeeto/endlessh https://github.com/shizunge/endlessh-go https://github.com/itskenny0/fail2ban-endlessh

    [–] SpaceCadet@feddit.nl 4 points 6 hours ago

    If it is your single purpose to create a blocklist of suspect IP addresses, I guess this could be a honeypot strategy.

    If it's to secure your own servers, you're only playing whack-a-mole using this method. For every IP you block, ten more will pop up.

    Instead of blacklisting, it's better to whitelist the IP addresses or ranges that have a legitimate reason to connect to your server, or alternatively use someting like geoip firewall rules to limit the scope of your exposure.

    [–] pHr34kY@lemmy.world 1 points 6 hours ago* (last edited 6 hours ago)

    I disabled ssh on IPv4 and that reduced hacking attempts by 99%.

    It's on IPv6 port 22 with a DNS pointing to it. I can log into it remotely by hostname. Easy.

    [–] MyNameIsIgglePiggle@sh.itjust.works 2 points 9 hours ago (1 children)

    Since I've switched to using SSH keys for all auth Ive had no problems I'm aware of. Plus I don't need to remember a bunch of passwords.

    But then I've had no training in this area. What do I know

    [–] nonentity@sh.itjust.works 2 points 9 hours ago (1 children)

    I’ve recently seen login attempts using keys, found it curious…

    [–] Laser@feddit.org 4 points 9 hours ago* (last edited 9 hours ago)

    Probably still looking for hosts that have weak Debian SSH keys that users forgot to replace. https://www.hezmatt.org/~mpalmer/blog/2024/04/09/how-i-tripped-over-the-debian-weak-keys-vuln.html

    [–] DaCrazyJamez@sh.itjust.works 30 points 16 hours ago (2 children)

    As a linux n00b who just recently took the plunge and set up a public site (tho really just for my own / selfhosting),

    Can anyone recommend a good guide or starting place for how to harden the setup? Im running mint on my former gaming rig, site is set up LAMP

    [–] psivchaz@reddthat.com 27 points 14 hours ago (3 children)

    The other poster gave you a lot. If that's too much at once, the really low hanging fruit you want to start with is:

    • Choose an active, secure distro. There's a lot of flavors of Linux out there and they can be fun to try but if you're putting something up publicly it should be running on one that's well maintained and known for security. CentOS and Debian are excellent easy choices for example.

    • Similarly, pick well maintained software with a track record. Nginx and Apache have been around forever and have excellent track records, for example, both for being secure and fixing flaws quickly.

    • If you use Docker, once again keep an eye out for things that are actively maintained. If you decide to use Nginx, there will be five million containers to choose from. DockerHub gives you the tools to make this determination: Download number is a decent proxy for "how many people are using this" and the list of updates tells you how often and how recently it's being updated.

    • Finally, definitely do look at the other poster's notes about SSH. 5 seconds after you put up an SSH server, you'll be getting hit with rogue login attempts.

    • Definitely get a password manager, and it's not just one password per server but one password per service. Your login password to the computer is different from your login to any other things your server is running.

    The rest requires research, but these steps will protect you from the most common threats pretty effectively. The world is full of bots poking at every service they can find, so keeping them out is crucial. You won't be protected from a dedicated, knowledgeable attacker until you do the rest of what the other poster said, and then some, so try not to make too many enemies.

    [–] DaCrazyJamez@sh.itjust.works 1 points 4 minutes ago
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    [–] horse_battery_staple@lemmy.world 19 points 15 hours ago* (last edited 14 hours ago) (1 children)

    Paranoid external security. I'm assuming you already have a domain name. I'm also assuming you have some ICANN anonymization setup.

    This is your local reverse Proxy. You can manage all this with a container called nginx proxy manager, but it could benefit you to know it's inner workings first. https://www.howtogeek.com/devops/what-is-a-reverse-proxy-and-how-does-it-work/

    https://cloud9sc.com/nginx-proxy-manager-hardening/

    https://github.com/NginxProxyManager/nginx-proxy-manager

    Next you'll want to proxy your IP address as you don't want that pointing to your home address

    https://developers.cloudflare.com/learning-paths/get-started-free/onboarding/proxy-dns-records/

    Remote access is next. I would suggest setting up wireguard on a machine that's not your webserver, but you can also set that up in a container as well. Either way you'll need to punch another hole in your router to point to your wire guard bastion host on your local network. It has many clients for windows and linux and android and IOS

    https://github.com/angristan/wireguard-install

    https://www.wireguard.com/quickstart/

    https://github.com/linuxserver/docker-wireguard

    Now internally, I'm assuming you're using Linux. In that case I'd suggest securing your ssh on all machines that you log into. On the machines you're running you should also install fail2ban, UFW, git, and some monitoring if you have the overhead but the monitoring part is outside of the purview of this comment. If you're using UFW your very first command should be sudo ufw allow ssh

    https://www.howtogeek.com/443156/the-best-ways-to-secure-your-ssh-server/

    https://github.com/fail2ban/fail2ban

    https://www.digitalocean.com/community/tutorials/ufw-essentials-common-firewall-rules-and-commands

    Now for securing internal linux harden the kernel and remove root user. If you do this you should have a password manager setup. keepassx or bitwarden are ones I like. If those suck I'm sure someone will suggest something better. The password manager will have the root password for all of your Linux machines and they should be different passwords.

    https://www.makeuseof.com/ways-improve-linux-user-account-security/

    https://bitwarden.com/help/self-host-an-organization/

    https://keepass.info/

    Finally you can harden the kernel

    https://codezup.com/the-ultimate-guide-to-hardening-your-linux-system-with-kernel-parameters/

    TLDR: it takes research but a good place to start is here

    https://www.digitalocean.com/community/tutorials/recommended-security-measures-to-protect-your-servers

    [–] psivchaz@reddthat.com 9 points 14 hours ago (1 children)

    Correct, horse battery staple.

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    [–] Hozerkiller@lemmy.ca 39 points 17 hours ago (1 children)

    I've gotta say this post made me appreciate switching to lemmy. This post is actually helpful for the poor sap that didn't know better, instead of pure salt like another site I won't mention.

    [–] Tablaste@linux.community 28 points 17 hours ago (1 children)

    I shared it because, out there, there is a junior engineer experiencing severe imposter syndrome. And here I am, someone who has successfully delivered applications with millions of users and advanced to leadership roles within the tech industry, who overlook basic security principles.

    We all make mistakes!

    [–] LordCrom@lemmy.world 13 points 15 hours ago (1 children)

    There's a 40 year I.T. veteran here that still suffers imposter syndrome. It's a real thing I've never been able to shake off

    [–] pulsewidth@lemmy.world 7 points 14 hours ago

    Just look at who is in the White House, mate - and not just the president, but basically you can pick anyone he's hand-picked for his staff.

    Surely that's an instant cure for any qualified person feeling imposter syndrome in their job.

    [–] phx@lemmy.ca 20 points 17 hours ago (2 children)

    Had this years ago except it was a dumbass contractor where I worked who left a Windows server with FTP services exposed to the Internet and IIRC anonymous FTP enabled, on a Friday.

    When I came in on Monday it had become a repository for warez, malware, and questionable porn. We wiped out rather than trying to recover anything.

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