VPN-Firewall Integration: A Strategic Analysis

Reading Time: 4 minutes

Category: Threat Intel

Author: Rob Maas

Integrating various network functions within a single device, such as combining VPN (Virtual Private Network) capabilities with firewalls, has become a common practice over the past few years. This consolidation offers benefits in terms of platform security features (i.e. user-based policies and Layer 7 inspection), simplicity and cost-effectiveness.

However, recent critical vulnerabilities in such setups have sparked a debate: Is it still prudent to combine these features on the same device?

The Appeal of Integrated VPN-Firewall Solutions

Integrating VPN functions within firewalls has been favored for several compelling reasons:

  • Leveraging all the capabilities that a device offers ensures that investments in technology yield maximum benefits.
  • Managing one device and one operating system is simpler and can lead to fewer administrative errors than juggling multiple systems.
  • Integration usually requires fewer changes to existing infrastructure, easing implementation burdens.
  • Fewer devices mean reduced hardware costs and operational expenses, allowing organizations to allocate funds to other critical areas.

The Risks of Consolidation

Despite the apparent advantages, there are significant security concerns to take into consideration. For starters, by consolidating various network functions you increase the attack surface If a vulnerability is discovered in one feature (such as the VPN service), it could potentially compromise the entire device, including its firewall capabilities. This risk highlights the danger of putting ‘all your eggs in one basket’.

Additionally, this can lead to a slower response to incidents. It is often easier to shut down or isolate a device which only holds a single feature.

It also leads to a complexity of management; managing multiple intertwined features to maximize security benefits can lead to more complex configurations.

The Recent Concerns

Recently, several high-profile vulnerabilities in popular firewall devices that also offer VPN services have come to light, raising serious security concerns. These issues have led to a reevaluation of whether these integrated systems are as safe as previously thought. It is also worth noting that every edge device (a device publicly reachable over the Internet) will always be a target of interest. They are easy to find and connect to, since they are publicly reachable.

This means that vendors will do their utmost best to keep these devices secure and having incident response procedures in place such as quickly releasing patches, send out information, and mitigation options, which has been proven in the events lately. It is up to you or your managed service partner to keep up with these updates and best practices.

Some of these concerns are also addressed in our Threat Talks: Does Remote Work.


Citrix Netscaler

TunnelCrack VPN

FortiOS SSLVPN buffer overflow

A Balanced Perspective

Despite recent vulnerabilities, for many organizations, the advantages of integrating VPN and firewall functionalities continue to outweigh the risks. The key lies in diligent management and operation.

Here’s what to consider:  

  • Proactive Maintenance
    It is crucial that devices are regularly updated with the latest security patches and monitored for unusual activity.

  • Strategic Resource Allocation.
    The savings from device consolidation should be redirected towards enhancing security measures that have more impact than separating the features.

  • Vendor Support
    Ensuring that the chosen technology vendor has robust incident response capabilities and a strong track record of addressing vulnerabilities quickly can mitigate potential risks.

While it is imperative to remain vigilant about potential security flaws, the integration of VPN and firewall features can still be a wise strategy if managed correctly.

That being said, for organizations prioritizing the highest levels of security, separating these features in protect surfaces and protecting each with dedicated security measures can offer greater control and reduced risk. This approach ensures that vulnerabilities in one service do not compromise the entire network.

Organizations must weigh the benefits of simplicity and cost savings against the potential risks and then make informed decisions based on their specific circumstances and threat landscape.

If you need assistance determining the best solution for your needs, don’t hesitate to contact us.