this post was submitted on 29 Aug 2024
65 points (98.5% liked)

Selfhosted

39435 readers
2 users here now

A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don't control.

Rules:

  1. Be civil: we're here to support and learn from one another. Insults won't be tolerated. Flame wars are frowned upon.

  2. No spam posting.

  3. Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it's not obvious why your post topic revolves around selfhosting, please include details to make it clear.

  4. Don't duplicate the full text of your blog or github here. Just post the link for folks to click.

  5. Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).

  6. No trolling.

Resources:

Any issues on the community? Report it using the report flag.

Questions? DM the mods!

founded 1 year ago
MODERATORS
 

Hi all,

I found a hobby in trying to secure my Linux server, maybe even beyond reasonable means.

Currently, my system is heavily locked down with user permissions. Every file has a group owner, and every server application has its own user. Each user will only have access to files it is explicitly added to.

My server is only accessible from LAN or VPN (though I've been interested in hosting publicly accessible stuff). I have TLS certs for most everything they can use it (albeit they're self signed certs, which some people don't like), and ssh is only via ssh keys that are passphrase protected.

What are some suggestions for things I can do to further improve my security? It doesn't have to be super useful, as this is also fun for me.

Some things in mind:

  • 2 factor auth for SSH (and maybe all shell sessions if I can)
  • look into firejail, nsjail, etc.
  • look into access control lists
  • network namespace and vlan to prevent server applications from accessing the internal network when they don't need to
  • considering containerization, but so far, I find it not worth foregoing the benefits I get of a single package manager for the entire server

Other questions:

  • Is there a way for me to be "notified" if shell access of any form is gained by someone? Or somehow block all shell access that is not 2FA'd?
  • my system currently secures files on the device. But all applications can see all process PIDs. Do I need to protect against this?

threat model

  • attacker gains shell access
  • attacker influences server application to perform unauthorized actions
  • not in my threat model: physical access
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 3 points 2 months ago (1 children)

Consider running some kind of file integrity monitoring. samhain, tiger, tripwire, to name a few.

considering containerization, but so far, I find it not worth foregoing the benefits I get of a single package manager for the entire server

Just do MAC with either AppArmor or SELinux.

[–] [email protected] 5 points 2 months ago

just do MAC

cries in NixOS