15 VPS Security Tips to Prevent Attacks on Your Server

Linux virtual private server (VPS) stands as a trusted choice for companies across the world.

The flexibility and power of Linux VPS make it a prime pick. Yet there’s a dark cloud hovering: cyber threats.

The facts cause alarm.

In March 2023, according to IT Governance, 41.9 million records, mainly drivers’ licenses, passport numbers, monthly financial statements, etc., were compromised by cyberattacks worldwide.

Additionally, the three biggest security incidents of May 2023 alone accounted for more than 84 million breached records – 86% of the month’s total. The easiest target? An inadequately secured server.

An inadequately secured VPS waits like a ticking time bomb, ready to blow a hole in your reputation, finances, and customer trust. Thankfully, fortifying your Linux VPS isn't string theory, but you have to practice diligence, expand awareness, and employ proven security measures.

In this guide, we’re going to talk about 15 VPS security tips. Simple, actionable, and indispensable, these strategies will convert your server from vulnerable to vault.

VPS security shields these digital environments from unauthorized access, malware, Distributed Denial-of-Service (DDoS) attacks, or further security breaches.

Can Linux VPS be hacked? Is it secure?

Linux VPS, though reputable for its robust security framework, is not impervious to threats.

Like any other system, vulnerabilities emerge, and hackers constantly prowl for any weak points by leveraging:

• Malware: Once malicious software infiltrates Linux, inside, it can compromise system performance, steal data, or even absorb the server into a botnet.
• Virtual machine instance: Hypervisors, which manage virtual instances, can be targeted. If a hacker gains access to one of the virtual instances, there's a potential risk to other virtual machines hosted on the same physical machine.
• Customer sensitive information: Your VPS often houses critical data, like user login credentials or personal customer information. Without appropriate security measures, cybercriminals excavate that data like a goldmine.

How VPS technology improves security

At its source, VPS technology relies on bare-metal servers, which inherently bolster security for web hosting. 

Bare-metal servers are physical servers dedicated exclusively to one tenant. This exclusivity ensures complete control over the hardware, eliminating multi-tenancy risks. With this control, there’s minimal chance for one user’s vulnerabilities to affect another's.

Next in line is the hypervisor.

This software marvel divides a bare-metal server into multiple VPS instances. By partitioning and sharing resources, it hosts several virtual environments on a single host machine. It remains isolated, often out of the general public's reach, curbing potential security breaches.

Source: Webpage Scientist

When we pit VPS against shared hosting, the former takes the prize.

One vulnerability can expose all hosted sites with shared hosting, but using VPS, even if you're technically “sharing” a bare-metal server, the partitioned and virtualized environments offer layers of security buffers, making VPS a safer bet.

15 tips for protecting your server security 

While technology has provided businesses with tools to scale and operate efficiently, it's also opened the gates to sophisticated cyber threats. Your server, the backbone of your online presence, demands unwavering protection.

A lapse in online safety isn't just a technical glitch; it's a breach of trust, a dent in reputation, and a potential financial pitfall. Which proactive measures should you take to shelter the impenetrable fortress of your server against cyber threats?

1. Disable root logins 

Root logins grant users the highest level of server access. By logging in as “root,” anybody can make whatever changes they want, clearly a huge risk. Administrators should ideally use a non-root user account with the necessary privileges and then switch to a root user when essential. 

By disabling direct root logins, they can shrink the attack surface.

Dropbox once experienced a data breach because an employee used a password from a site that had been hacked.

2. Monitor your server logs

Logs record all activities that happen on your server. Regular log monitoring allows you to spot any unusual patterns or potential security breaches. Early detection means the difference between thwarting a hacking attempt and dealing with a full-blown crisis.

For example, if a shoplifter visits multiple times, the shop owner can detect patterns in their behavior. Similarly, consistent log analysis signals repeated unauthorized access attempts.

3. Remove unwanted modules and packages 

The Equifax breach in 2017 affected 143 million people. The culprit turned out to be an unpatched vulnerability in the Apache Struts web application software, an unnecessary module for most.

What does this mean?

Every pre-installed software package or module can potentially introduce vulnerabilities, and not all are necessary for your operations. Removing unused or obsolete packages reduces the number of possible entry points.

4. Change the default SSH port and start using SSH keys

Secure shell (SSH) is commonly used to safely access servers. However, attackers often target the default port 22. By simply changing this to a non-standard port, you can dodge many automated attack attempts.

Moreover, using SSH keys - cryptographic keys – instead of passwords fortifies security. SSH keys are more complex and harder to crack than even the strongest passwords.

Major companies encourage the use of SSH keys for authentication. GitHub, for one, emphasizes its security benefits over traditional passwords.

5. Set up an internal firewall (iptables)

iptables function as an internal firewall, controlling the traffic that goes in and out of your server.

By filtering and setting rules on IP packets, you can decide which connections to allow and which to block. This gives you another shield against hackers.

Major web platforms, such as Amazon Web Services, frequently emphasize the importance of setting up correct iptables rules to secure resources.

6. Install an antivirus

While Linux is often praised for its robust security, it's not immune to threats.

Installing antivirus on your VPS helps detect and neutralize malicious software to keep your data safe and uncompromised. Just as software has protected millions of computers worldwide by detecting threats in real time, an antivirus for your server continuously scans files and processes to keep malware at bay.

7. Take regular backups

In 2021, the ransomware attack on the Colonial Pipeline resulted in a shutdown and disrupted fuel supplies all across the East Coast of the United States.

Taking regular backups of your data protects you and your server from such disasters. By having backups, you can restore everything to its previous state in the event of a data loss incident.

8. Disable IPv6

Disabling IPv6, the latest version of the internet protocol, can prevent potential vulnerabilities and attacks. But it may also introduce new risks if not properly configured and secured.

Disabling IPv6 reduces the attack surface and potential exposure to cyber threats.

9. Disable unused ports 

Every open port on your VPS is a potential gateway for cyberattacks. By disabling ports you don't use, you're essentially shutting unnecessary open doors. It makes it harder for intruders to get in.

Disabling unused ports lowers the risk of human error.

10. Use GnuPG encryption 

GNU Privacy Guard (GnuPG) encryption helps encrypt and sign your data and communication. It provides a secure layer so your data remains confidential and tamper-proof.

In 2022, a ransomware variant called "LockFile" was discovered that used GnuPG encryption to encrypt files on infected systems. The ransomware was particularly sneaky, targeting specific organizations and slipping past standard security protocols.

11. Install a rootkit scanner

Rootkits are malicious software platforms that can gain unauthorized access to a server and remain hidden. Installing a rootkit scanner neutralizes the hidden threats.

In 2023, the cybersecurity community identified a novel rootkit named "MosaicRegressor" that specifically targeted Linux servers. Alarmingly, it could slip past conventional security protocols with ease.

12. Use a firewall

Your firewall is your server’s bouncer for your server. It checks all the data coming in and going out. With the right rules and guidelines, firewalls stop dodgy requests or certain unwanted IP addresses.

For instance, businesses with a DDoS attack problem could often mitigate the effects using well-configured firewalls.

13. Review users' rights 

Make sure only the right people keep your server safe. We often look out for dangers from the outside, but sometimes, the troublemaker might be calling from inside the house.

In November 2021, a glaring example surfaced when a former employee of the South Georgia Medical Center in Valdosta, Georgia, downloaded confidential data onto one of their own USB drives a day after quitting the job.

Regularly reviewing and updating user permissions prevents potentially disastrous situations like this.

14. Use disk partitioning 

To conduct disk partitioning, you have to split your server's hard drive into multiple isolated sections so that if one partition faces issues, the others remain functional.

15. Use SFTP, not FTP

File transfer protocol (FTP) was once the go-to method for transferring files, but it lacks encryption, meaning data sent via FTP is vulnerable to eavesdropping. Secure file transfer protocol (SFTP) was then developed to work similarly to FTP with the added bonus of data encryption.

Think about when you transmit customer details or confidential business data. Using SFTP is similar to sending a sealed, secure courier package, whereas using FTP is like sending a postcard – anyone can read it if they intercept it.

How to fix common VPS security vulnerabilities

Cyber threats are often closer than you think. Even minute vulnerabilities can invite hackers to infiltrate your systems. Recognizing weak spots and acting promptly fortifies your VPS security.

Peruse these common pitfalls to learn how to circumvent them.

1. Weak passwords

The hackers' favorite gateway is a frail password. According to a survey by the UK's National Cyber Security Centre, 23.2 million victims used "123456" as passwords that were later stolen.

A whopping 81% of company data breaches are due to stolen, weak passwords. 

Fix: Enforce a password policy that requires alphanumeric characters, special symbols, and varying cases to reduce the reliance on easily guessable phrases. Password manager software can generate and store complex passwords. 

Recommendations from the National Institute of Standards and Technology call for people to create passwords that are "easy-to-remember phrases, long" — a series of four or five words mashed together.

2. Obsolete software

Running outdated software is akin to leaving your doors unlocked. Cybercriminals constantly look for known vulnerabilities in old versions the same way house thieves look for overgrown lawns and full mailboxes.

Consider the WannaCry ransomware attack, which exploited older Windows versions and affected over 200,000 computers.

Fix: You need to regularly update and patch software. IT teams can adopt automated systems, like unattended upgrades for Linux, to keep software updates timely.

3. Unprotected ports

An open port is like an unlocked door for hackers. For instance, the Redis database vulnerability resulted from unprotected ports.

Fix: Use tools like Nmap to scan and identify open ports. Close unnecessary ports and employ firewalls like UFW or iptables to restrict access. The fewer doors you have open, the fewer ways to sneak in.

4. Insufficient user permissions 

Overprivileged users spell disaster. Having analyzed quarterly reports for 500 companies, Accenture reported that 37% of cyberattacks in businesses originate with internal actors. 

Fix: Set up the principle of least privilege (PoLP). Assign roles based on necessity and audit user permissions routinely. Ensuring that each user has only the permissions they need minimizes potential damage.

5. Lack of supervision 

Without a vigilant eye on server operations, irregularities go unnoticed and pave the way to potential threats.

Take a situation where an unexpected surge in traffic occurs. This might be a DDoS attack, but without proper supervision, someone could easily misconstrue it as a sudden influx of genuine users.

Fix: Invest in monitoring tools. Periodically review logs and set up alerts for unusual incidents because you can't protect what you can’t monitor.

6. No function-level control 

Function-level control goes beyond general user permissions and dives into the specific tasks a user can perform.

Say an employee in a company's finance department has access to view and modify payroll data. Without clear boundaries, that employee could effect unintended changes, errors, or even malicious activities.

Fix: Implement function-based access control (FBAC) systems to make sure that users only access the functions vital to their role. Regular audits of these permissions further fine-tune and secure access.

By controlling functions, you're not just limiting access; you're molding a secure, role-appropriate environment for each user.

Guarding the gates: the imperative of VPS security 

As cyber dangers grow trickier and more common, an unprotected server can lead to big problems. You might lose important data – you might lose the faith people have in you. 

Keeping a VPS safe is like tending to a garden; you've got to keep at it. By staying updated and following good safety tips, you're building a strong defense.

And remember, by guarding your server, you're showing your users you really care about their trust.

Dive deep into the basics of VPS hosting and learn more about its types, benefits, and best practices to follow to make VPS hosting work for you.