Writeup from 2022 that I assume is mostly still valid. TLDR:
- 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.”)
- Move as much activity outside the core maximum privilege OS as possible.
- OP doesn’t mention immutable OS, but I assume they help a lot.
- 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:
- Disable or remove things you don’t need to minimise attack surface.
- Stay updated. Configure a cron job or init script to update your system daily.
- Don’t leak any information about you or your system, no matter how minor it may seem.
- Follow general security and privacy advice.
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
Wow, this is very confirmed kills copypasta energy… at any rate, while I’m sure hundreds of hours of security podcasts have taught you many things, again, the original point being disputed is “Mainstream Linux is less secure than macOS” and a side point about the risk of not firewalling a modern mainstream Linux distro on public wifi.
As you state, network traffic is handled by the kernel network stack. The firewall (iptable rules, not magic) is network stack software that runs on that same Linux kernel. In what regard is the local firewall itself magic where “CVE stuff can[n’t] happen” on public wifi? If macOS is more secure inherently here, how? If that answer is “bSd MaGIc” okay, sure… do you understand what percentage of exploits are “hacks” in the 1990’s become root with memory exploit on hardware way in 2025? I challenge you to find a case, even at a hacking event of someone raw banging on a closed port on a modern mainstream Linux distro until they overflow into something. This is also a Starbucks… I don’t think anyone is rocking their 0-days at random Starbuckses.
You keep talking about non-default setups on fringe distros. Nobody is arguing Puppy Linux from 2010 with Limewire installed is secure to put on the modern internet at Starbucks, although I would give 99.999999% odds nobody will sidejack your insecure X11 stack at a random Starbucks even on unfirewalled Puppy Linux from 2010, even with Limewire.