16 Steps To Secure you Linux VPS (Virtual Private Server)

Cybercriminals are constantly devising new ways to infiltrate and exploit vulnerabilities. As a VPS owner, understanding the intricacies of VPS security and implementing robust measures is paramount to protecting your valuable data and ensuring smooth server operations.

This comprehensive guide delves into the essential aspects of securing your VPS, equipping you with the knowledge and actionable steps to fortify your virtual private server against cyber threats. We will explore common Linux vulnerabilities, highlight essential security elements to monitor, and provide a step-by-step walkthrough of effective security measures.

Understanding Linux Vulnerabilities and Security Fundamentals

While Linux is generally recognized for its strong security posture, every system has inherent vulnerabilities that attackers can exploit. Understanding these vulnerabilities is crucial for implementing effective security practices. Some common threats to Linux systems include:

• Malware: Malicious software designed to infiltrate and damage computers or steal sensitive information. This includes Trojans, ransomware, viruses, and spyware.

• Sniffing attacks: Cyberattacks involving eavesdropping network traffic using packet sniffers to intercept and extract sensitive data.

• Brute-force attacks: Hacking attempts that involve systematically trying different login credentials until successful access is gained.

• SQL injection: Exploiting vulnerabilities in web applications to gain access to server databases.

• Cross-site scripting (XSS): Exploiting client-side vulnerabilities to inject malicious code into websites, compromising user accounts or stealing information.

• No function-level control: Lack of proper access verification and privilege escalation allowing unauthorized users to gain root privileges.

• Broken authentication: Compromising user credentials through unencrypted data, weak passwords, or poorly configured application session timeouts.

Before diving into specific security measures, it is essential to understand the critical areas to focus on within your VPS:

• VPS hosting security: The security measures implemented by your VPS provider, including firewalls, security updates, and malware detection.

• Server software: The security updates and configurations of the server software you are using, such as operating systems and applications.

• SSH connection: Secure Shell (SSH) connections, which are crucial for managing your VPS remotely, require strong authentication and encryption.

• Root access and login: Limiting root access and implementing secure login practices are essential to prevent unauthorized access to your server.

• Passwords and credentials: Choosing strong passwords and implementing multi-factor authentication to safeguard your VPS accounts.

• Firewall: Configuring a firewall to block unauthorized access and malicious traffic.

• FTP connection: Ensuring secure file transfer through SFTP, which encrypts data during transfer.

• User permissions and privileges: Granting appropriate permissions to different users and groups to restrict access to sensitive resources.

• Server logs: Monitoring server logs for suspicious activity and identifying potential security breaches.

Essential Steps to Secure Your VPS

Now, let's delve into practical steps you can take to secure your VPS and mitigate potential cyber threats:

1. Choose a Secure VPS Provider

The first line of defense lies in selecting a reputable VPS provider that prioritizes security. Look for providers offering robust security features such as:

• Web application firewalls: Protect your applications against common attacks, such as SQL injection and XSS.

• PHP hardening (Suhosin): Improve PHP security against vulnerabilities.

• Open_basedir protection: Restrict PHP script access to specific directories, preventing access to sensitive files.

• Full-stack server protection (BitNinja): Provide comprehensive protection against cyber threats.

• Advanced DDoS mitigation: Safeguard against distributed denial-of-service attacks.

• Anti-malware (Monarx): Continuously scan your VPS for malware and suspicious activity.

• SSL certificates: Encrypt data transmission between your website and visitors, ensuring secure communication.

2. Change the Default SSH Port

The default SSH port (22) is commonly targeted by automated scanners, making it vulnerable to brute-force attacks. To enhance your security, change the listening port for SSH:

1. Access your VPS via SSH.

2. Edit the SSH configuration file: nano /etc/ssh/sshd_config.

3. Locate the line Port 22 and change it to your desired port, for example, Port 1026.

4. Save the changes and restart the SSH service.

5. Connect to your VPS using the new SSH port.

3. Disable Root Login

The root user account holds the highest privileges on your VPS and can access all system resources. Disabling root login through SSH mitigates the risk of unauthorized access.

1. Access your VPS via SSH.

2. Edit the SSH configuration file: nano /etc/ssh/sshd_config.

3. Set PermitRootLogin=no.

4. Save the changes and restart the SSH service.

4. Use Strong Passwords

Weak passwords are easily guessed by attackers. Implement strong passwords with a combination of uppercase and lowercase letters, numbers, and special characters. Consider using a password manager to generate and store strong passwords securely.

5. Implement SSH Keys for Authentication

SSH keys provide a more secure alternative to password-based authentication. This involves generating a pair of keys: a public key stored on the server and a private key kept secure on your device.

1. Generate SSH keys on your local machine using ssh-keygen -t rsa.

2. Add the public key to the authorized_keys file on your VPS.

3. Access your VPS using SSH and the private key.

6. Configure Internal Firewall (IP Tables)

IP Tables is a powerful firewall built into Linux. You can configure it to block malicious traffic and allow only necessary connections.

1. Install IP Tables on your VPS: sudo apt-get install iptables.

2. List current IP Tables rules: sudo iptables -L -v.

3. Configure IP Tables rules based on your security requirements.

7. Set Up UFW Firewall

Uncomplicated Firewall (UFW) is a user-friendly interface for IP Tables. It offers a simpler way to manage firewall rules.

1. Enable UFW: sudo ufw enable.

2. Check the firewall status: sudo ufw status.

3. Customize UFW rules based on your needs.

8. Use SFTP for Secure File Transfer

Secure File Transfer Protocol (SFTP) encrypts data during file transfer, preventing eavesdropping attacks.

1. Connect to your VPS via SFTP using sftp user@server_ipaddress.

2. Transfer files securely between your local machine and your VPS.

9. Configure Fail2Ban

Fail2Ban monitors system logs and automatically blocks IP addresses that exhibit suspicious activity, such as multiple failed login attempts.

1. Install Fail2Ban: sudo apt-get install fail2ban.

2. Check the Fail2Ban status: sudo systemctl status fail2ban.

3. Configure Fail2Ban to block specific types of attacks.

10. Install an Antivirus

Protect your VPS from malware by installing a reliable antivirus solution. ClamAV is a popular open-source antivirus that can effectively detect and quarantine malicious files.

1. Install ClamAV: sudo yum install clamav-server clamav-data clamav-update clamav-filesystem clamav clamav-scanner-systemd clamav-devel clamav-lib clamav-server-systemd.

2. Run a full system scan for malware.

11. Use a Malware Scanner

Complement your antivirus with a malware scanner to detect emerging threats. Monarx, provided by Hostinger, offers automated malware scanning and removal capabilities.

1. Access the Monarx malware scanner in your hPanel.

2. Run a malware scan to identify and remove malicious files.

12. Enable a VPN for Your VPS

A Virtual Private Network (VPN) encrypts your internet traffic and masks your IP address, adding an extra layer of security.

1. Install a VPN on your VPS, such as OpenVPN.

2. Configure the VPN to route traffic through a secure tunnel.

13. Review User Permissions

Grant appropriate permissions to different users to restrict access to sensitive resources.

1. Create user groups with specific permissions.

2. Add users to these groups and assign appropriate permissions.

14. Disable IPv6

While IPv6 is the next generation of internet protocol, it can introduce security vulnerabilities. Disabling IPv6 mitigates these risks.

1. Edit the sysctl configuration file: sudo nano /etc/sysctl.d/99-sysctl.conf.

2. Add the following lines to disable IPv6: net.ipv6.conf.all.disable_ipv6 = 1, net.ipv6.conf.default.disable_ipv6 = 1, and net.ipv6.conf.lo.disable_ipv6 = 1.

3. Save the changes and apply them: sudo sysctl -p.

15. Monitor Server Logs

Regularly review server logs to detect any unusual activity, including failed login attempts, suspicious traffic, or system errors.

1. Navigate to the /var/log directory.

2. Examine system logs such as syslog for potential security threats.

16. Keep Software Up to Date

Outdated software is susceptible to known vulnerabilities. Regularly update your operating system, applications, and dependencies to patch security flaws.

1. Use the package manager on your Linux distribution to update packages.

2. Enable automatic updates to receive updates promptly.

Conclusion

Securing your VPS is essential for protecting your data and ensuring your server's stability. By implementing the security measures outlined in this guide, you can create a strong defense against cyber threats and maintain the integrity of your VPS.

Remember, security is an ongoing process. Stay informed about new vulnerabilities and emerging threats, and continually review and update your security practices to adapt to the ever-evolving landscape of cybersecurity. By prioritizing security, you can enjoy peace of mind knowing that your valuable data and applications are protected.