How to Secure a Linux VPS: A Hardening Checklist

A fresh VPS is exposed to the internet from the second it boots, and automated bots start probing it within minutes. Here is a practical, day-one hardening checklist that closes the doors attackers actually use — no deep Linux expertise required.

1. Update everything first

Before anything else, apply all available updates. A freshly-provisioned image is often weeks or months old and may already be missing security patches. Then enable automatic security updates so you are not relying on memory.

2. Create a non-root user

Never do day-to-day work as root. Create a normal user, give it sudo for when you need elevation, and use that. If something goes wrong or an account is phished, you have not handed over the whole machine. (If sudo is not set up yet, see user not in sudoers.)

3. Lock down SSH

SSH is the front door, and brute-force bots hammer it constantly. The essentials: use key-based login, disable password auth, disable direct root login, and add brute-force protection. This matters enough to have its own guide — how to harden SSH.

4. Turn on a firewall

Default-deny is the goal: block everything, then allow only the ports you actually use (SSH and your game or app ports). A simple firewall (ufw or firewalld) takes minutes and instantly shrinks your attack surface. If you cannot reach a service afterwards, you probably have not opened its port.

5. Run only what you need

Every running service is another potential way in. List what is listening on the network and switch off anything you are not using — old databases, test servers, default web apps. The smaller the surface, the fewer vulnerabilities can ever apply to you.

6. Add brute-force protection

Tools like fail2ban watch your logs and automatically ban IPs that fail to log in too many times. It will not stop a determined targeted attacker, but it makes your server invisible to the constant background noise of credential-guessing bots.

7. Apply least privilege

Give every user, service and database account the minimum rights it needs — no more. If one is ever compromised, least privilege is what stops a small breach becoming a total one. It applies to file permissions, database users and app accounts alike.

8. Back up off the server

Security is not only about keeping attackers out — it is about recovering fast when something goes wrong. Keep automated backups, store at least one copy off the server, and test a restore occasionally. A good backup is what turns a compromise from a disaster into an afternoon.

You do not need to be a security expert — doing the basic eight above puts you ahead of the overwhelming majority of servers that get breached.

The quick checklist

• Fully updated, with automatic security updates on.
• A non-root sudo user for daily work.
• Key-only SSH, no root login, brute-force protection.
• A default-deny firewall, only needed ports open.
• Only the services you actually use, running.
• Least privilege for users, services and databases.
• Automated, tested, off-server backups.

Do these once on day one and revisit them whenever you add something new. For the game-server-specific layer on top, see our game server security checklist.