This is a short list of things to take into account to have some basic security in a VPS.

Regular system updates

• Use sudo apt update && sudo apt upgrade regularly to fetch and apply updates.
• For kernel updates, use sudo apt full-upgrade to ensure all packages are updated.
• Clean up with sudo apt autoremove to remove unnecessary packages.

Enable unattended upgrades

Used for ensuring your Ubuntu server automatically installs security updates without manual intervention.

Install with unattended-upgrades.

sudo apt install unattended-upgrades

Configure by editing /etc/apt/apt.conf.d/50unattended-upgrades to suit your needs.

To check if it’s working

You can check the timestamp files.

ls -l /var/lib/apt/periodic/

Or manually run a test:

sudo unattended-upgrade --dry-run --debug

Logs are located at /var/log/unattended-upgrades/.