The Illusion of Safety: Why VPNs Aren’t Foolproof as a result of the “TunnelVision” Security Vulnerability!

The Flawed Foundation— Facing the Limitations of VPN Security now that Every VPN is at Risk!

A critical security vulnerability called “TunnelVision” that affects virtual private networks (VPNs) has been discovered. Researchers identified an unpatchable flaw that allows attackers to siphon off data from VPNs without being detected. The flaw exploits DHCP protocols to divert VPN traffic, enabling attackers to read the data in clear text. Your online activity through ISPs is traditionally considered at risk to third-party interference. Such as leak of your privacy and security if not using a VPN service to establish a secure connection to keep you safe. 

TunnelVision VPN Vulnerability Details

  1. TunnelVision allows attackers who have already compromised a network to divert a VPN user’s traffic outside of the encrypted VPN tunnel by manipulating DHCP protocols, specifically DHCP option 121.
  2. By rerouting traffic outside the VPN tunnel traveling over an ISP connection, attackers can siphon off data in clear text from the VPN connection without any indication to the user or VPN software that an attack is occurring.
  3. Even with VPN “kill switch” features enabled, the researchers found no VPN servers disconnected them during their TunnelVision attack.
  4. The vulnerability is worsened by VPNs often being used on public Wi-Fi networks with weak security protections, providing attack vectors.
  5. While mitigations like network namespaces exist, they are not widely implemented and can introduce other issues like connectivity problems.
  6. The core issue is that VPNs were never intended as a dedicated security tool, but rather just an encrypted tunnel for connectivity. Their overreliance as a security control is a misconception.
  7. Other VPN shortcomings mentioned include lack of anonymity, potential logging by VPN providers, no protection for endpoints/malware, and centralized architecture exposing attack surfaces.

When looking at the unpatchable TunnelVision flaw and how it enables undetectable data siphoning from the VPN connection through diverting ISP traffic, we realized very quickly we needed to rethink “why a VPN” should matter so much. 

It highlights that VPNs were never intended to be a security tool; they were designed as connectivity tools for remote access. However, too many organizations and individuals have been relying on VPNs as a defensive measure, possible a result of marketing being too good. This has caused a misunderstanding of their purpose and usage, giving folks a false sense of true security.

Risks of VPNs

To further understand your risks in just relying on a VPN, here are some additional reasons why VPNs are not a cure all security tool some would want you to believe:

  1. Endpoint vulnerability: VPNs only encrypt the data in transit between the client and the VPN server. If the endpoints (client or server) are compromised, the data can be accessed in clear text. This can put you at risk to malware, virus threats and other types of hacking targeting your systems due to VPN security risks.
  2. Limited protection: VPNs do not protect against many types of attacks, such as man-in-the-middle attacks, DNS hijacking, or malware infections on the endpoints.
  3. Split tunneling: If split tunneling is enabled, some traffic may bypass the VPN tunnel, exposing it to potential interception.
  4. Lack of access control: VPN typically provides all-or-nothing access to the internet service network, lacking granular levels of security controls based on user roles or resource sensitivity.
  5. Centralized architecture: secure VPN servers can become a single point of failure or a target for attacks, potentially exposing the entire network if compromised.
  6. Scalability and performance issues: As the number of VPN users increases, the VPN server’s performance and scalability can become a bottleneck, leading to degraded performance or connectivity issues.

VPN Security Future as a Cybersecurity Tool

While VPNs can provide a secure remote access solution for online security, they should be used in conjunction with other security features and controls not relied upon as a comprehensive security or online privacy measures, especially now. A defense-in-depth approach, including encryption of your actual traffic before entering a VPN, endpoint protection, access controls, and encryption at various layers, are all necessary additional recommendations for robust security.


Can you Trust a VPN?

This becomes critical as many use free VPN services to secure themselves online in a belief that their IP-address with be protected and the likelihood of a data leak or a data breach will be greatly reduced. The benefits of a safe VPN for secure access to protect your privacy while using public internet traffic has been its number one use case, especially when using public WI-FI.  But its important to realize with TunnelVision’s security vulnerability being discovered is that our understanding of VPN tools and how VPNs work to provide safety and security is now in question.

Rethinking VPN Security

It is crucial for users to be aware of the potential risks associated with using VPN services, especially free ones, as they may not always offer the level of security and privacy protection that they claim to provide. It has always been important to thoroughly research and choose a reputable VPN service that has strong security measures in place to protect your data and privacy. However, the benefits of a VPN now with TunnelVision vulnerability, and its unpatchable flaw our previous assumptions have been flipped on their head. We need to look at adding additional layers of security services such as our Warden with EDR that stops all known bad and unknown code from executing and causing damage to your systems. Your network security and ability to prevent data exposure while keeping you safe online needs to go back to basics with encryption of your internet data from your IP-address, before your VPN creates a secure encrypted connection.

Future User Security

Users should also be cautious of relying solely on VPNs as a means of protecting their online security and should implement other cybersecurity measures, such as using strong passwords, enabling two-factor authentication, and keeping their devices and software up to date.
Overall, while VPNs can be a useful tool for enhancing online privacy and security, it is important for users to understand their limitations and to take additional steps to protect their data and personal information. 


The discovery of the “TunnelVision” security vulnerability has shaken the foundation of VPN security, revealing an unpatchable flaw that allows attackers to divert VPN traffic and access data without detection. While VPNs were originally designed for connectivity rather than security, many have come to rely on them as a primary defense, overlooking their limitations. Endpoint vulnerability remains a critical concern, as VPNs only encrypt data in transit, leaving endpoints susceptible to malware and other threats. Additionally, VPNs lack comprehensive protection against various types of attacks and may suffer from scalability and performance issues. In light of these shortcomings, it’s essential to adopt a defense-in-depth approach to cybersecurity, incorporating encryption, endpoint protection, and access controls. Users must also exercise caution when selecting VPN services, as free options may not offer adequate security measures. Moving forward, prioritizing endpoint security and implementing additional layers of protection, such as Warden with EDR, is crucial for safeguarding against evolving threats and ensuring robust online security.