Reducing the Attack Surface: Why ZTNA Outshines VPNs for Remote Work Security

The shift to remote work has expanded the digital landscape in which organizations operate, creating both new opportunities and new challenges. VPNs (Virtual Private Networks) have long been the standard for securing access across multiple sites, but as home offices—often notoriously insecure—have become part of this network, organizations are facing a growing attack surface.

In today’s work-from-anywhere reality, VPNs may connect secure enterprise networks with less secure environments, like home networks. While employees might be accessing legitimate work applications, the devices connected to their home network can be vulnerable, potentially spreading malware via unsecured machines connected through the VPN. This is especially concerning when you consider that 82% of data breaches involve a human element. The more users and devices connected to an organization's network, the greater the risk.

This is where Zero Trust Network Access (ZTNA) comes into play as a smarter, more secure alternative.

VPNs vs. ZTNA: A Smarter Approach to Remote Access

ZTNA significantly reduces the attack surface by enabling more granular control over who can access what. Instead of extending network access to all devices like a VPN, ZTNA operates on the principle of least privilege—establishing application-to-user connections rather than providing blanket network access. This essentially creates a more defined, contained perimeter for potential attacks, limiting the scope of exposure.

While VPNs expose the application backend to users, ZTNA continuously validates the trustworthiness of both users and devices. By granting access only to the front-end portal of an application, ZTNA ensures that even if a user is compromised, a cybercriminal can't easily leapfrog their way across the organization’s entire network. This dynamic, context-aware approach shrinks the attack surface and minimizes cyber risk.

Minimizing Cyber Risk with Continuous Validation

One of the main issues with VPNs is their “one-and-done” approach to authentication. Once a user is granted access to the network, they can remain connected for extended periods, as long as their credentials are valid. This poses a significant risk, as anyone gaining unauthorized access to the device (e.g., via stolen hardware) could have full access to the organization’s resources.

ZTNA goes a step further by continuously validating access in real-time. It doesn’t just confirm credentials at login, but also:

- Validates endpoint security, such as checking if patches are installed or the device is domain-connected.

- Authenticates the user’s identity using multi-factor authentication (MFA).

- Monitors user behavior to ensure activities align with normal patterns, such as typical working hours and locations.

ZTNA leverages the pillars of Zero Trust, assuming that no user or device should be inherently trusted, and requires continuous revalidation. For example, if a user’s device suddenly begins dumping memory files using PowerShell or demonstrates unusual behavior, ZTNA will flag the risk, increasing the device's risk score and potentially terminating the connection. Similarly, if a malware infection is detected, ZTNA can instantly revoke access.

This ability to assess risk continuously and react in real-time to potential threats significantly lowers the cyber risk compared to the static nature of VPN authentication.

Enhanced Scalability for Modern Work Environments

Scalability is another area where ZTNA shines. VPNs often require a significant amount of bandwidth to function effectively, especially since they grant users broad access to the entire network. In contrast, ZTNA only connects users to specific applications they are authorized to access, reducing the need for the heavy bandwidth required by VPNs.

Legacy VPN technology, which typically connects traffic through on-premises VPN firewalls or concentrators, struggles to scale efficiently. In today’s agile business environments, where remote work has become the norm, this approach no longer delivers the performance or user experience required.

ZTNA, however, is built for the future. Its application-to-user connectivity scales rapidly and doesn’t bog down network performance, ensuring high availability and consistent delivery without impacting the user experience. This scalability makes ZTNA ideal for organizations growing their remote workforce or adopting flexible work arrangements.

The Future of Secure Remote Access

As organizations continue to embrace hybrid and remote work models, reducing the attack surface is critical to minimizing cyber risks. VPNs, while useful in the past, expose too much of the network and can’t provide the dynamic security needed in a modern business landscape.

ZTNA offers a superior solution by creating a more precise security perimeter, enforcing continuous validation, and enabling scalable, application-specific access. With its ability to minimize risk and improve scalability, ZTNA represents the future of secure, remote access in a rapidly changing digital world.