How To Secure A Linux Server

Securing a Linux server is crucial for multiple reasons, as servers often hold critical data and provide essential services that can be targets for malicious attacks. Whatever the reason for using the server, it is exposed to risks such as:

👺Hacking Attempts: Uninvited guests may try to break into your server to steal data, take control, or using your server for ilegal activities such as sending spam, host illegal content or attack other systems.
🦠Viruses and Malware: Harmful programs can infect your server, slowing it down, damaging files, or spying on your activities.
💣Overloading with Traffic (DDoS Attacks): Attackers can flood your server with too many requests, causing it to crash and making it unavailable to real users.
❗️Stealing Important Information: Criminals may try to access sensitive information like passwords, customer details, or financial records.
💰Ransomware Attacks: Your data can be locked by attackers who demand money to unlock it (one of the most commonly used methods).

Why It Is So Important to Secure a Linux Server

Securing a Linux server is primary in safeguarding critical infrastructure, sensitive data, and ensuring business continuity. Linux servers often serve as the foundation for hosting applications, databases, and enterprise systems, making them prime targets for cyber threats. A security lapse can expose an organization to data breaches, financial loss, operational disruptions, and reputational damage.

Unauthorized access is one of the most significant risks, as attackers can exploit vulnerabilities to gain control over the server, leading to data theft, system compromise, or even using the server for launching further attacks. Sensitive data, such as customer information and intellectual property, must be shielded from malicious actors to prevent identity theft, fraud, and legal consequences. Moreover, Distributed Denial of Service (DDoS) attacks and ransomware campaigns can incapacitate servers, resulting in costly downtime and data loss.

Robust security measures, including firewalls, intrusion detection systems, and timely software updates, are vital to mitigate these threats and maintain service availability. Also, we have created a guide to make it easier for you to go through this process and solve the ❌ security problem for your server.

Installation Requirements

❗️The main actor of our article is the Linux operating system (make sure you have the same operating system, we will work on Debian).

disable ports forwarding until your system is secured (disabling port forwarding initially, your server is hidden from the internet while you set it up safely. Once it’s ready, you can enable port forwarding knowing that your server is better protected)
if you are not working directly on your server with a physical connection, you will need remote access, so ensure that SSH is functioning properly.
Keep your system up-to-date (i.e. sudo apt update && sudo apt upgrade on Debian based systems).
configuring network (without a properly configured network, your server won’t be able to connect to other systems or provide services to users.)
configuring mount points in /etc/fstab
creating the initial user accounts (this involves setting up non-root user accounts that will be used to manage and operate the server)

❗️Using the root account for everyday tasks is risky because mistakes can cause severe damage. Creating individual users improves security and accountability.