Linux Security: Best Practices for Safe Operations

Linux has a reputation for being secure and safe. While there are some inherent features and architecture that make Linux a secure operating system, it’s not invincible. Here’s some background on Linux security and some best practices for safe operations. 

What is Linux?

First things first: What is Linux? Linux is an operating system (OS) that can operate on computers, servers, mainframes, mobile devices and a variety of other devices. Linux is an open source OS. That means its source code is publicly and freely available. Anyone can view the code, modify it and share it.

Linux is a great fit for nearly every organization because of its flexibility. Because Linux is open source, it’s a great OS for companies that need high customization. The code is flexible, and the platform works with a wide variety of tools and applications. You can implement Linux with nearly any hardware architecture. 

The qualities that really make Linux unique, however, are its reliability, security and stability. Its open source heritage allows any user to identify and fix bugs quickly, rather than having to report an error to a vendor and wait for them to get around to fixing it. You can use it for your mission-critical systems knowing that it performs well. Linux security is also robust with frequent updates and patches. The community that catches errors and makes improvements means that Linux and security go hand in hand.

What is Linux security?

Linux security is a term for all the features, tools, best practices and strategies that keep Linux secure. Linux security involves keeping the core Linux component, called the kernel, safe, as well as all of the Linux applications that are running. 

Some aspects of Linux security are inherent to the operating system. Security is built into Linux’s architecture with default limited user privileges and defined file ownership. Linux has default low-level permissions so few people have the ability to change code on a whim. This is an idea called the “principle of least privilege,” where people are given the least amount of access needed to perform their jobs in order to prevent people from making drastic mistakes. 

In addition to the inherent security features, other aspects of security on Linux systems involve correct user behavior. Linux users need to prioritize correct configuration, updates, patches, best practices and proper Linux security support. 

The advantages of using Linux security features

Using Linux security features comes with many advantages. Many other operating systems approach security like a burden. However, using Linux’s security features makes it easy to keep your organization safe and still do the work you need to do in the way you need to do it. Users have several advantages when they use Linux security features, including: 

• Proactively preventing threats. Organizations used to have a reactive approach to security, but Linux security should be proactive. Firewalls are important Linux security features that prevent security threats from happening in the first place. Many Linux distros also help you stay a step ahead of bad actors with automated updates that can install patches without requiring full system reboots, empowering you to keep working while you beef up your security. 
• Joining strong communities. Open source software comes with the major plus of having strong communities. Communities are a significant Linux security feature because users thoroughly review code and collaborate to fix issues. Bugs are public, which allows people to identify them quickly and create strong and secure operating systems. Communities and forums, like SUSE’s, also foster collaboration and creativity so you can build your instance in the best way possible. 
• Leveraging customization and flexibility. Security doesn’t have to be a straitjacket. With Linux’s security features, you can keep your data safe while still customizing everything from your desktop environment to terminal emulators. Linux is flexible, too. You can prioritize security with Linux’s features while still incorporating your legacy architecture, using a variety of different distros and scaling as your business grows. 
• Processing efficiently. Protect your data without slowing down your processing. Linux’s flexibility allows you to choose the most efficient and effective tools for your tasks so you can keep your organization safe while still checking off to-dos. Linux security features like selective updates and live kernel patching allow your Linux distros to keep processing while you install updates. You can even define kernel parameters to balance security and network performance. 

Threats to security for Linux

Although Linux has many advantages, users should also be aware of threats to it. The more aware users are of the threats, the better they can identify them and protect against them. 

Network-based attacks are a severe threat to Linux. If there’s an error in the public code, anyone can find it, and they can choose to fix it or choose to exploit it. Although every operating system can be targeted by network-based attacks, these attacks are particularly damaging to Linux systems. Linux systems act as servers for web, email, file sharing and database services, which exposes them to constant probing and attacks over the network. If anything happens to the network, the entire system suffers. 

Linux systems also face the threat of root account exploits. Major system-wide changes can only be made by a root user, the one person who has access to the entire operating system. Keeping users’ privileges limited is a good practice. However, if a bad actor does gain access to the root user account — usually through weak credentials or system vulnerabilities — there’s no stopping them. This is extremely dangerous, although it’s easily prevented with a secure enterprise Linux server. 

Another threat to Linux systems is kernel flaws. Kernels are the core components of Linux operating systems. If there’s a flaw in the kernel, that flaw’s implications can affect the entire system. Kernel-level flaws can result in privilege escalation, system crashes, malware spreading and more. 

Best practices for securing Linux systems

It’s important to remember that security for Linux is never a one-and-done checklist. It’s a constant effort. Cyber threats, hackers, data breaches and more are constantly evolving in their sophistication, so your security strategies have to keep up. 

Luckily, all of the threats listed in the section above can be largely prevented by following some simple best practices. Here are some key best practices to keep your Linux-based servers safe and protect your data:

• Follow Certified Security Guidelines. Security certifications, such as Common Criteria (CC), CIS Benchmarks, and FIPS 140-2 compliance, provide best practices for configuring and maintaining Linux security. Organizations should align their security practices with these certifications to ensure hardened environments.
• Use multiple authentication methods. Linux’s flexibility allows it to support multiple authentication methods, such as username/password combinations, Secure Shell (SSH) keys, smart cards, biometrics and digital certificates. Often, you may need more than one authentication method to verify users’ identities, stop hackers and protect sensitive data. You can view SUSE’s authentication guide for more tips. 
• Remove unneeded features. The more applications and modules you have open, the more attack surface is available for potential threats to hit. Any services you’re not using should be removed. This will limit the chances for breaches. You can also limit module loading by blacklisting the modules that aren’t necessary for your server’s functionality. As a bonus, your servers will run more efficiently, too. 
• Install regular updates. Installing updates is an important part of security for Linux. Patches and fixes are your best way of being proactive against malicious actors and keeping your system safe. Linux is particularly easy to install updates on, as it usually doesn’t require an entire system restart. Users can usually install updates with minimal disruption compared to other OSs. You can also configure automatic updates for your Linux server to ensure critical security updates are always installed.
• Monitor logs. Linux servers keep logs of all activity, such as server performance, security, error messages, logins and any underlying issues. You should be regularly checking your logs for suspicious activity as well as any performance issues or maintenance needs. 
• Enable firewalls. Securing Linux servers is easy with firewalls. Firewalls control the incoming and outgoing traffic on your servers and can stop bad actors before they get into your operating system. 
• Enable SELinux for Mandatory Access Control. Security-Enhanced Linux (SELinux) is a security module that enforces mandatory access control (MAC) policies to limit what processes and users can access. Unlike traditional Linux permissions, SELinux prevents unauthorized access—even if an attacker gains root privileges. It helps contain security breaches by enforcing least-privilege policies and preventing applications from performing unintended actions. Ensure SELinux is set to Enforcing mode for maximum protection, and review security policies to fit your server’s needs.

How SUSE supports security for Linux

SUSE supports security for Linux through our suite of products and services, which offer customers advantages like:

• Technical support. SUSE supports your Linux security around the clock. Our 24/7, follow-the-sun support is always here to answer your questions, help manage user access and point you to helpful documentation. Our experts are here to support your security efforts whenever you need us. 
• Updates. The vast majority of Linux security threats can be prevented with updates. SUSE supports your security by offering patches and updates. On average, SUSE releases nine security pages per month so you can stay up to date. 
• Monitoring. SUSE software monitors your system for vulnerabilities and alerts you when it finds one. SUSE’s logging provides comprehensive auditing of system events and security-related activities
• Identity and access management. Solidify your Linux security with SUSE’s identity and access management tools, including role-based access control and two-factor authentication. 
• Certified Security Standards. SUSE Linux Enterprise meets industry security standards and certifications such as Common Criteria (CC), FIPS 140-2, and CIS Benchmarks, ensuring compliance with regulatory and enterprise security requirements.
• Support for Mandatory Access Control (MAC). SUSE supports security frameworks like AppArmor and SELinux, which enforce mandatory access control policies to restrict unauthorized access to critical system components. With fine-grained security policies, these tools help prevent privilege escalation, contain security breaches, and protect sensitive data. SUSE provides guidance and tools to configure and manage MAC security policies effectively.
• Optimized security for specific applications. SUSE enhances security for business-critical workloads like SAP HANA with firewall predefined configurations that minimize attack surfaces. With firewalld integration, SUSE protects SAP workloads without disrupting essential services.

Achieve Linux security today

SUSE is dedicated to supporting your Linux instances and distributions. We were founded on open source principles and still adhere to values of transparency, flexibility and choice. Our enterprise security solutions help you enjoy those values while still keeping your organization safe. 

An example of SUSE Linux security capabilities in action is the University of Luxembourg and its sub-structure Luxembourg Centre for Educational Testing (LUCET). LUCET had to expand to meet the increasingly high numbers of students who needed online testing services. The LUCET team switched to SUSE Linux Enterprise Server, which gave them the security and scalability they needed. SUSE solutions provided LUCET with consistent security standards from core to edge. Students’ test scores and other information were safe, and the IT team experienced a 90% reduction in troubleshooting time. 

You shouldn’t have to choose between enterprise-grade security and fast processing, flexibility and other benefits. SUSE’s support offers a win-win for your data protection and your tailored business needs. Learn more about SUSE’s secure enterprise Linux server here. 

Linux security FAQs

Is Linux safer than Windows?

While no operating system can guarantee a completely error-free experience, Linux provides a reliable and secure foundation for critical operations, ensuring stability and efficiency in high-stakes environments. Because Linux’s open source code is transparent, public scrutiny usually catches and corrects errors quickly.

Which is the most secure Linux OS?

Most Linux OSs are very secure. Which OS is “most secure” will likely depend on the tasks you need it to do, what your existing infrastructure looks like, how many servers you have, how diverse your IT environment is and other factors. 

How do you securely manage Linux user permissions?

Securely manage Linux user permissions using the principle of least privilege. This means that you shouldn’t give a user any more access than they absolutely need for their job. You should also review user permissions regularly to make sure that everyone’s access is correct. You can also review access control lists (ACLs) to make sure permissions are correct. More user permission best practices are having strong authentication in place and monitoring user activity. 

What Security Certifications Apply to Linux?

• Common Criteria (CC) – Internationally recognized security certification for IT products, including Linux distributions.
• FIPS 140-2 – Federal standard for cryptographic security in Linux systems.
• CIS Benchmarks – Best-practice guidelines for secure Linux configurations.
• SOC 2, ISO 27001, and PCI DSS – Compliance standards that ensure Linux security in cloud and enterprise environments.