Linux Server Security Best Practices

Securing servers from bad access and cyber threats is crucial. Server administrators and cybersecurity teams need to make sure the servers are protected. Many people trust Linux servers because they think they are very safe.

Compared to Windows and macOS servers, Linux servers have fewer weaknesses. But, Linux can still face cyberattacks. The main problems for Linux servers are privilege escalation, memory issues, and sharing too much information. Cyber attackers use these issues to get into a Linux system and take data.

Reports from places like The National Vulnerability Database (NVD) and Crowdstrike show that every year, there are more problems with Linux. For example, in 2020, there were 1,958 issues reported. In 2021, there was a 35% increase in bad software attacking Linux, compared to 2020. And in 2022, almost 1.7 million new bad softwares were found for Linux, which is 650% more than the year before.

This makes following Linux server security best practices important If you want to discover tips to make your Linux server more secure, this guide is perfect for you.

What is a Linux Server?

A Linux server is a computer system running the Linux operating system designed to provide various services, resources, or applications to other devices or users on a network. Unlike desktop computers, which are used for personal tasks, a Linux server is optimized to handle tasks like hosting websites, managing databases, serving files, or running applications that require constant availability and reliability.

Linux servers are popular in the world of web hosting, cloud computing, and enterprise environments due to the stability, security, and flexibility offered by the Linux operating system. They come in various forms, from physical servers to virtual servers in the cloud, and they play a crucial role in supporting the infrastructure of the internet and various online services.

Why does Linux Server Security Matter?

Linux server security is of utmost importance for several reasons:

Preventing Unauthorized Access:

Security measures on Linux servers help prevent unauthorized individuals or malicious entities from gaining access to sensitive data, applications, or system resources. This is crucial for protecting the integrity and confidentiality of information.

Data Protection:

Linux servers often store valuable data, including user information, financial records, or proprietary business data. Securing the server ensures that this data remains safe from unauthorized access, theft, or tampering.

System Stability:

A compromised server can lead to system instability, disruptions, and downtime. Security measures help maintain the stability and reliability of the server, ensuring it functions optimally without unexpected interruptions.

Network Security:

Linux servers often serve as key components in networks, and their security is integral to overall network security. A secure server helps prevent unauthorized access to the network and protects against potential attacks that may compromise the entire infrastructure.

Compliance Requirements:

Many industries have specific security and privacy regulations that organizations must adhere to. Implementing robust security measures on Linux servers helps meet compliance requirements and avoids legal and financial consequences.

Protection Against Malware and Exploits:

Linux servers are not immune to malware and other cyber threats. Security measures, such as regular updates, firewalls, and antivirus solutions, help protect against malware, exploits, and vulnerabilities that could be exploited by attackers.

Maintaining Reputation:

For businesses and organizations, a secure Linux server is essential for maintaining a positive reputation. Security breaches can result in loss of trust from clients, customers, or users, which can have long-lasting consequences.

Mitigating Risks of Data Loss:

Security measures, including regular backups and disaster recovery plans, help mitigate the risks of data loss. In the event of a security incident, having backups ensures that critical data can be recovered.

Best Practices For Linux Server Security

Ensure Strong Protection:

Begin with strong protection for your server. Make tough passwords and turn on two-factor authentication (2FA). Passwords should be at least ten characters, with special symbols and a mix of upper and lower-case letters.

Use SSH Key Pairs:

While passwords have their place, Secure Shell (SSH) key pairs offer a more secure way to access servers. SSH keys make it much harder for attackers to guess. They rely on cryptographic key pairs, which are more secure than passwords. Though they might be a bit less user-friendly, the extra security they provide is worth it.

Keep Your System Updated:

Regularly update your Linux server to maintain its security. New patches and updates fix recently found vulnerabilities and security flaws. Not updating your server can make it vulnerable to attacks. Consider automating updates to ensure you don’t miss important security fixes.

Remove Unnecessary Software:

While adding new software might seem appealing, not all packages are necessary. The more software you add, the bigger the potential for security vulnerabilities. Periodically review your software and cybersecurity measures, removing anything unnecessary. Regular maintenance reduces the risk of security breaches and keeps your server running well.

Linux distributions have a superuser account called “root” with elevated administrative privileges. Keeping the root login enabled can pose a security threat. To enhance your Linux system's security, disable this login. Create a new user account and give it elevated (sudo) permissions to install programs and perform administrative actions.

Check and Close Open Ports:

Open ports can expose information about your network, making it susceptible to attacks. Regularly scan for open ports and close any that are not in use. Tools like netstat can help you identify open ports and secure your server by closing them.

Enable a Firewall:

A firewall protects your system from unauthorized access. Check and configure the firewall to ensure server security. iptables is a great tool to filter incoming, outgoing, and forwarded IP packets. It helps create rules for receiving or sending traffic from specific IP addresses, safeguarding against unauthorized access and Distributed Denial of Service (DDoS) attacks.

Harden Your Linux System:

Use security systems like SELinux or AppArmor to control processes' access to files in the file system. SELinux significantly enhances Linux server security. AppArmor, used in Ubuntu, operates similarly. Profiles are created for each application, specifying which files the application can access.

Security Audits Are Important:

Regularly conduct security audits to identify and address potential security issues. Even the most secure server can become vulnerable to new threats without proper updates and checks.

Regularly Create and Maintain Backups:

Backups are crucial for Linux server security. Rsync is a popular choice for data backups in Linux. Regularly test backups to ensure they contain the correct files and can be quickly restored in case of data loss.

Linux Server Security Is a Continuous Process

While the tools and configurations mentioned above boost Linux server security, remember that security is an ongoing process. Regular checks, software updates, and data backups are essential. Without vigilance and continuous self-education, security measures may not be effective.