Lynis is an open source security tool to perform in-depth audits. It helps with system hardening, vulnerability discovery, and compliance. The security tool is free to use and open source software (FOSS). When creating a policy for your firewall, consider using a “deny all, allow some” policy. So you deny all traffic by default, then define what kind of traffic you want to allow.

• Most software packages are a collection of one or more tools bundled together.
• Although there are several combinations possible, it is not fine-grained.
• In such a case, the default daily or weekly backups are just what you need to get things back to normal.
• The software for the system is typically selected during the installation phase.

An updated Linux server will be compatible with the latest security methods and tools, so you can explore various cybersecurity options. However, you may not be able to enable current Linux updates or distributions in older Windows or Mac systems. With that in mind, you should only set up a new Linux system on a computer that is relatively new. In addition to this, you should maintain documentation for all your security settings, policies, and system configurations. This documentation is an essential part of your disaster recovery plans and should be updated whenever you change your security configuration.

Why perform system hardening on Linux systems?

To take SSH security to the next level, you may also enable two-factor authentication. In this approach, you receive a one-time password on your mobile phone, email or through a third-party aunthentication app. Before you go for this approach, make sure that you have added your own public key to the server and it works.

This checklist is created based on years of expertise in the field of Linux security. Before making changes to systems, special care should go into testing. This is even more important for changes made to systems that are in production. For those items that you don’t fully understand, follow up by doing more research first instead of just copy-pasting configuration snippets. This checklist has been created based on our knowledge and additional research.

Close Unnecessary Ports

To thwart SSH bruteforce attacks, you can use a security tool like Fail2Ban. You may also add selected users to a new group and allow only this group to access SSH. The idle timeout interval is the amount of time an SSH connection can remain active without any activity. You must remember or note down linux hardening and security lessons the port number otherwise you may also not access your servers with SSH. If you are aware of SSH basics, you know that the SSH configuration files are located at /etc/ssh/sshd_config. In this article, I’ll share some practical ways to improve SSH security and thus securing your Linux servers.

However, just securing the perimeter via a firewall is not enough. In the cloud, the VMs should be configured to run in a Zero Trust network, as opposed to on-premise VMs, which are in a demilitarized zone. Any communication between VMs is considered relatively secure. If you have servers connected to the internet, you likely have valuable data stored on them that needs to be protected from bad actors. Prepare yourself mentally because this is going to be a long list.

System update

By staying vigilant and proactive in log analysis, administrators can maintain a robust security posture for their VPS, ensuring the early detection and mitigation of potential risks. Proper care for software patch management help with reducing a lot of the related risks. The activity of installing https://remotemode.net/ updates often has a low risk, especially when starting with the security patches first. Most Linux distributions have the option to limit what packages you want to upgrade (all, security only, per package). Make sure that your security updates are installed as soon as they come available.

In reality, however, the vast majority of SSH key pairs are even more complex. For this reason, SSH key pairs should be one of the first measures implemented when adopting a proactive server security strategy. Linux kernel and its related files are in /boot directory which is by default as read-write. Changing it to read-only reduces the risk of unauthorized modification of critical boot files.

Linux Network Level Hardening

It is best not to mix application functions on the same server to avoid differing security levels on the same server. The extra security authentication required could be a QR code, for example, displayed on a different device to the one being used. Make sure you check out a number of 2FA packages before you uninstall one. Look at the different options available and choose one that has a solid reputation for improving security. If you want to implement 2FA on your server, you can do it fairly easily.

Google Authenticator generates time-based one-time passcodes (TOTPs) that users must enter alongside their regular password during SSH authentication. This dynamic authentication method significantly reduces the risk of unauthorized access even if login credentials are compromised. The implementation involves configuring the OpenSSH server to support 2FA, installing and configuring the Google Authenticator PAM module, and then enabling 2FA for specific users. To understand the detailed steps of this kindly refer this article.