Linux Hardening Guide | Madaidan's Insecurities
madaidans-insecurities.github.io

Writeup from 2022 that I assume is mostly still valid. TLDR:

  1. Mainstream Linux is less secure than macOS, Windows, and ChromeOS. (Elsewhere: “[iOS/Android] were designed with security as a foundational component. They were built with sandboxing, verified boot, modern exploit mitigations and more from the start. As such, they are far more locked down than other platforms and significantly more resistant to attacks.”)
  2. Move as much activity outside the core maximum privilege OS as possible.
  3. OP doesn’t mention immutable OS, but I assume they help a lot.
  4. Create a threat model and use it to guide your time and money investments in secure computing.

Once you have hardened the system as much as you can, you should follow good privacy and security practices:

  1. Disable or remove things you don’t need to minimise attack surface.
  2. Stay updated. Configure a cron job or init script to update your system daily.
  3. Don’t leak any information about you or your system, no matter how minor it may seem.
  4. Follow general security and privacy advice.
    • BCsven@lemmy.ca
      0·
      16 days ago

      Some distros ship with no firewall enabled, some newbie using public WiFi is going to be less secure.

      A pain with OpenSUSE tumbleweed is firewall and SELinux by default, but it forces you to learn about security if you need to setup SAMBA or other connections to your machine

        • BCsven@lemmy.ca
          0·
          16 days ago

          Last time I tried Ubuntu, it had a firewall but it wasn’t active by default. Unless something changed in the last few years.

          No firewall means your system is going to get scanned to see if anything is open or exploitable

            • BCsven@lemmy.ca
              0·
              16 days ago

              People hang out on public WiFi sometimes with packet sniffing and other tools to exploit people. Especially some distros don’t have X server remote display locked down.

              If you want to know what is open or exploitable CVE you can run a script that discovers all CVE exploits against a machine

                • BCsven@lemmy.ca
                  0·
                  16 days ago

                  To answer all your questions I’d need some time, I’d have to go back to the 100s of hours of 2.5admins and security podcasts. But to clarify an exploit doesn’t have to be an open service especially if you aren’t running a firewall. Some bombard your network adapter into buffer overun etc, but network traffic is handled by the kernel stack. A good firewall drops packets instead of letting them all into the public interface and kernel TCP stack. Where CVE stuff can happen.

                  I’m not saying Linux can’t be hardened , but because it is user editable and not locked down like Mac, you have a lot of things people can alter (or not alter) by hand or packages that can leave you open.

                  There’s a reason we have AppArmor and SELinux, yet some don’t bother to use those tools.

                  There was something with discord? Discourse? screen sharing that used x11 forwarding, and was on by default. I want to say Ubuntu. When it was news I checked by SUSE install and thankfully its disabled by default. But also the reason Linux distros are moving to Wayland because X11 is a security problem.

                  Ubuntu ufw off by default https://documentation.ubuntu.com/server/how-to/security/firewalls/index.html