Secure Remote Login via SSH - How a VPN Can Help

In an increasingly interconnected world, the ability to securely access remote systems and devices has become an integral part of modern business operations. As organizations expand their digital footprint, transitioning to the cloud, and embracing remote work, the significance of ensuring secure remote login via SSH (Secure Shell) cannot be overstated.

Although there are many means and ways to facilitate connections with a remote server, the two most used protocols are Secure Shell (SSH) for Linux-based machines and Remote Desktop Protocol (RDP) for Windows-based machines. In this blog, we will learn more about Secure Shell and how using a business VPN solution can help in facilitating secure remote login using SSH.

What is SSH?

Secure Shell, or Secure Socket Shell (SSH), is a protocol that enables secure connectivity to remote machines via a text-based interface. Targeted primarily at system administrators and network professionals, SSH ensures security for those who need to manage remote systems.

Secure Shell (SSH) comprises of two essential components: the client and its corresponding server-side counterpart. The SSH client resides on your local machine, while the server-side element takes its place on the remote device. As the client tries to establish a connection, a vital step involves credential verification. SSH offers various types of verification mechanisms:

• Password-Based Verification: The traditional method involves providing a password for authentication. While this remains an option, many experts recommend bolstering security by complementing it with multi-factor authentication (MFA) for an extra layer of protection.
• Public Key Authentication: Widely considered one of the most secure methods, public key authentication involves generating a pair of cryptographic keys – a public key and a private key. The public key resides on the server, while the private key remains solely with the client. This approach not only minimizes the risk of password-based attacks but also simplifies the login process.

Why does an SSH connection need to be protected?

SSH is designed to provide encrypted communication over an insecure network, such as the Internet. While SSH itself is quite secure, there are still several reasons why additional protection might be necessary:

• Brute Force Attacks: Attackers might try to guess the SSH credentials (username and password) through brute force attacks. They use automated tools to systematically try various combinations of usernames and passwords until they find the correct one.
• Key Compromise: SSH primarily uses key-based authentication, which is more secure than password-based authentication. However, if the private key used for authentication is compromised or stolen, an attacker could gain unauthorized access. To protect against this, private keys should be stored securely, encrypted with strong passphrases, and rotated regularly.
• Server Vulnerabilities: Servers running SSH software can have vulnerabilities that might be exploited by attackers. Regular software updates and patches are crucial to fixing these vulnerabilities. If a server is compromised, attackers could potentially intercept or manipulate SSH traffic.
• Insider Threats: Even with secure authentication mechanisms, individuals with legitimate access to SSH keys and credentials can misuse them. Organizations need to implement proper access controls, monitor user activity, and revoke access promptly when an employee or contractor leaves the organization or changes roles.
• Man-in-the-Middle Attacks: While SSH is designed to prevent eavesdropping, attackers could still attempt man-in-the-middle attacks to intercept or alter the communication between the client and server.

Overall, SSH is a robust and widely used protocol for secure remote access, but the security of the entire system depends on various factors, including proper configuration, user practices, and additional security measures. One of the many ways to secure the SSH connections to your remote machines is routing the connection via VPN. In this blog, we will learn how to set up a secure remote login via SSH through VPN.

VPN’s role in securing remote login to SSH

A Virtual Private Network (VPN) can play a significant role in securing remote login to SSH (Secure Shell) by adding an additional layer of security to the communication between the client and the server. Here's how a VPN enhances security for remote SSH logins:

Encryption: VPNs encrypt the data transmitted between the client (your computer) and the VPN server. This encryption adds a layer of confidentiality to your SSH communication.

Access Control: A VPN can restrict access to the network, ensuring that only authorized users can connect. This enables additional authentication before users even reach the SSH login stage.

Protection from Network-based Attacks: Using public Wi-Fi or untrusted networks can expose your SSH connection to various network-based attacks. A VPN creates a secure "tunnel" over these networks, protecting your data from potential threats like packet sniffing and man-in-the-middle attacks.

Bypassing Firewalls and Restrictions: In some cases, SSH might be blocked by firewalls or network restrictions. A VPN can help bypass these restrictions by encapsulating the SSH traffic within its encrypted connection, allowing you to connect to your SSH server even when regular connections are blocked.

Reducing Exposure to the Internet: By requiring users to first connect to a VPN before accessing SSH, you reduce the direct exposure of your SSH server to the internet. This can potentially limit the attack surface and provide an additional layer of defense against unauthorized access.

How UTunnel Simplifies Secure SSH Login 

UTunnel streamlines the deployment of VPNs and the setup of Zero Trust Access, ensuring the security of SSH connections. By deploying a UTunnel server and configuring firewall rules on the SSH server, access can be restricted solely to connections originating from the IP address of the UTunnel server. This arrangement ensures a confidential and encrypted line of communication between clients and SSH servers, granting access solely to users connected to the UTunnel server through the UTunnel VPN client application.

Furthermore, UTunnel’s OneClick Access, its Zero Trust Application Access (ZTAA) solution seamlessly supports SSH. This innovative feature simplifies secure SSH access, eliminating the need for users to connect to the UTunnel server via a VPN client. Via OneClick Access, users can securely access protected SSH servers directly within the UTunnel web dashboard, from their web browser. Also, OneClick Access offers more stringent and fine-tuned access controls for SSH connections, ensuring that users are exclusively granted entry to designated resources. This effectively thwarts lateral movement and fortifies the security posture.

For diverse needs such as remote work or server administration, UTunnel presents an uncomplicated approach to bolstering SSH connections.

Conclusion

It's important to note that while a VPN can greatly enhance the security of remote SSH logins, it's not a replacement for good SSH security practices. You should still implement strong authentication methods, disable password-based authentication in favor of key-based authentication, keep your SSH server and software updated, and follow other best practices to ensure the overall security of your SSH connections.

Remember that security is a multi-layered approach, and using both a VPN and proper SSH security practices together can provide a more robust defense against potential threats. UTunnel Secure Access emerges as a commendable choice, effectively addressing the VPN aspect of this equation.