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Linux Server Security: 10 Best Practices for Hardening & Security

Linux Server Security

Linux servers are great for hosting business websites. With the right security in place, they can become a powerhouse that will provide you with years of service.

In this blog post, we will discuss 10 best practices for securing Linux servers from attackers and other malicious users. You’ll learn how to harden your server against attacks, prevent unauthorized access, and more! These are important factors in securing a shared web hosting service.

Here are the top ten best practices you can use to harden your Linux servers and prevent attackers from taking them over:

Tips for Hardening Linux

1.) Use strong, unique passwords

One of the easiest ways to protect your server is by using strong and unique passwords. Using short passwords or phrases is a bad idea because they can be easily guessed by automated tools.

Password cracking programs are widely available, so you must use passwords that cannot be found in the dictionary or from studying keyboard patterns. It’s also important to change your password regularly and never share it with anyone.

Long passwords that are unique to your server are ideal. You can use a password manager like LastPass to generate and store complex, random passwords that are very difficult for attackers to crack.

2.) Generate an SSH key pair

If you’re using SSH to connect to your server, it’s important that you generate an SSH key pair. Using passwords for authentication is very insecure because they can be easily guessed or compromised by brute force attacks.

Using a public/private key pair ensures that only someone with the private key can gain access to the system and nobody else will be able to. This is commonly referred to as asymmetric encryption. It’s also a good idea to encrypt your private key with a strong password for additional security.

Although SSH keys are not as easy to use as passwords (at least at first), they provide a much higher level of security and are well worth the extra effort.

3.) Routinely update server software

Keeping your server up to date with the latest security patches is extremely important. If you don’t upgrade software regularly, attackers can exploit known vulnerabilities and take over your system.

You should always run the latest version of Linux available for your distribution. It’s also important to make sure that all other applications running on the server are up to date. When it comes to selecting a distribution, we frequently use Ubuntu on VPS solutions, or CentOS on shared hosting solutions.

4.) Enable automatic updates

Most Linux distributions have a feature called “automatic updates” that will automatically install security patches and other upgrades when they become available. This is a great way to make sure your server is always up to date, without having to worry about it yourself.

You should enable automatic updates on all of your servers, and test them regularly to ensure they are working correctly.

5.) Don’t leave unnecessary software installed

It’s a bad idea to install and leave software on your server that you don’t actually need. Unnecessary applications increase the attack surface of your system, thereby introducing vulnerabilities that can be exploited by attackers.

You should also remove any unneeded packages after installing them because they will still exist in the operating system’s repositories. This means an attacker could discover them later and exploit them to gain access to your system.

6.) Disable booting from external devices

It’s a good idea to disable booting from external devices like USB drives or CD/DVDs. This will prevent attackers from installing malware on your system by using removable media.

If you’re using a desktop system, it’s also important to disable booting from internal devices like the network card and hard drive.

7.) Close hidden, open ports

It’s important to close any hidden open ports on your server. These are ports that are not normally visible to the user but can be used by attackers to gain access to your system.

Unnecessary ports should be closed, and you should only open ports that are actually required for your server to function. You can use the netstat command to view all of the active network connections and their associated port numbers.

8.) Scan log files with Fail2ban

Fail-safe bans are a great way to protect your server against hackers, brute force attacks, and other unauthorized login attempts. When you create a Fail-safe ban, it will monitor log files for specific patterns that indicate someone is trying to break into your system.

If an incorrect password or suspicious activity is detected by Fail-safe, it will automatically blacklist the offending IP address and prevent them from attempting to log in again.

It’s a good idea to periodically scan your log files for signs of suspicious activity using Fail-safe so you can block offenders as soon as possible.

9.) Perform routine security audits

It’s a good idea to perform regular security audits on your system. There are many tools available that can identify any weaknesses in your server configuration and report them back so you can fix the problem immediately.

Without regular security audits, your server may be vulnerable to attack and you may not even know it. That’s why this is an important step in protecting your server from attacks.

You should also consider hiring a professional security audit company to perform a comprehensive security assessment on your system.

10.) Make frequent offsite backups

Always make sure you have regular backups of your server, and that they are stored offsite. Backups come in handy if an attack or other disaster causes permanent data loss.

It’s important to test the recovery process regularly so you know that it works properly and backups are actually useful when something goes wrong.

The rsync application is a great way to back up your data in Linux. It comes with a number of built-in options that make it easy to create reliable backups without having to worry about data loss.

Final Thoughts on Hardening Linux Web Servers

Linux is a popular target for attackers because it’s used in so many different types of environments. From small businesses to large enterprises, Linux servers are found in almost every type of organization.

While you may be fine for a while, if you’re not taking the necessary steps to protect your Linux server you’re putting yourself at risk. Linux servers can be hardened and made more secure by following the above best practices. If you follow these steps, your server will have a lower chance of being hacked or suffering other security problems in the future.

The most important step is to audit your system regularly and take the time to test the recovery process. If you do this, it will be easier than ever before to protect and keep your server secure.

Disclaimer: WebCitz, LLC does not warrant or make any representations concerning the accuracy, likely results, or reliability of the information found on this page or on any web sites linked to from this page. This blog article was written by Timothy A in his or her personal capacity. The opinion(s) expressed in this article are the author's own and may not reflect the opinion(s) of WebCitz, LLC.