5 VPN split tunneling security risks and how to prevent them

1. Exposing sensitive data

The biggest split tunneling security risk is also the simplest. Unencrypted internet traffic at the application level and outside the secure VPN tunnel could be read by someone monitoring the connection, including your internet service provider or hackers. If you’re not careful, you could accidentally mix in sensitive data requests with unencrypted traffic, potentially leading to a data breach.

You should be particularly wary of data exposure when using the same app for both personal and work purposes. Web browsers are the most common culprits, with many remote workers keeping personal services open right next to their business accounts or other corporate resources. By using split tunneling to make your browser exempt from corporate VPN limitations, you’re putting both yourself and your company at risk.

2. Bypassing corporate security

Businesses often implement complex security measures to protect their infrastructure from unauthorized access, and setting up a virtual private network is a key part of the puzzle. By forcing all network traffic through a secure remote VPN server, the organization can concentrate its defenses in one spot.

Split tunneling actively subverts many of these security measures. For instance, your company may deliberately route traffic via a private DNS (Domain Name System) setup to automatically block access to known phishing and malware-hosting websites. By using VPN split tunneling to reach them, you could put the entire corporate network in danger.

3. Giving attackers a way in

By using an unmonitored VPN route, you don’t just bypass static security measures — you hide your online activity from your company’s cybersecurity experts. The IT department continuously monitors network traffic for anomalies using sophisticated intrusion detection systems (IDS) and intrusion prevention systems (IPS) to identify potential cyberattacks.

When you use split tunneling, some of your internet traffic escapes this oversight. If hackers were to compromise your device via these channels, it’d become a Trojan horse to the rest of the organization — a means for criminals to infiltrate the corporate network and steal valuable data.

4. Allowing latent malware to take root

Malware rarely takes noticeable action as soon as you download it. In most cases, it quietly works behind the scenes to take root. Once the infection of the end-user’s device is complete, the malware begins its lateral movement across the network, following instructions from the command and control server.

If all your traffic is routed via a corporate VPN, your organization’s cybersecurity measures may be able to detect this traffic to and from the cybercriminals’ servers, alerting them to the cyberattack. However, if you accidentally use split tunneling to access an infected app, the outbound traffic can go unnoticed, and the hacker may access the network. Once your device becomes infected, the malware can spread regardless of whether you continue to use split tunneling or not.

5. Failing to comply with regulations

To operate in certain markets, companies must follow stringent data protection regulations, including ensuring adequate endpoint security when employees work remotely. If a business fails to adhere to these standards, it can face fines, have its reputation damaged, and even be forced to cease operations.

In some cases, the use of split tunneling may put your company in danger even if there appears to be little risk of data theft. Using split tunneling to create unauthorized exceptions to compliance guidances may lead to your organization being fined for failing to meet its obligations arising from compliance policies.

Split tunneling security risks in practice

To illustrate how split tunneling security risks materialize, let’s review a scenario that many employees have likely encountered in the past: Doing a little work over lunch break.

It’s noon, and Alice is ready to head off for a quick bite. Unfortunately, she hasn’t finished compiling an important report that’s due in a few hours. Alice decides to take her work laptop with her and finish the report while connected to the nearby café’s free Wi-Fi hotspot.

To access the internal data for her report, Alice connects to her company’s VPN. This secures her connection, preventing anyone lurking on the café’s Wi-Fi network from spying on her online traffic. While the data is being transferred, Alice figures she might do some online shopping. But there’s a catch — her corporate VPN connection is very restrictive, automatically blocking access to her favorite shopping platform.

Alice decides to get the best of both worlds. She uses one browser to work on her report, keeping it protected by an encrypted VPN connection, and creates a split tunnel for the second browser to access the store. Though it might seem clever at first, this solution immediately exposes Alice to multiple serious security risks.

First, if Alice visits an insecure or compromised website, cybercriminals on the café’s Wi-Fi could intercept the unencrypted traffic or attempt to deliver malware. Second, the websites she’s visiting may have been blocked by her corporate VPN for security reasons. By stumbling onto a malicious website, Alice could be lured into downloading infected files or become a victim of drive-by downloading. In either case, Alice’s work computer would be compromised.

How to minimize VPN split tunneling security risks 

Incidents related to VPN split tunneling can be detrimental to both your personal data security and your organization’s integrity. The key to minimizing split tunneling security risks is to follow good online hygiene practices as you explore the internet, both at work and at home.

• Only let trusted apps access the internet directly. Traffic from apps you download from unverified sources could lead to exploits and allow attackers to infiltrate your computer. However, such threats can be monitored by a corporate VPN and similar internet security solutions and then neutralized with endpoint protection.
• Stick to reliable websites that use HTTPS encryption. Shady websites may tempt you with free file downloads, but they’re likely to throw in malware or spyware as a bonus.
• If you plan to browse without VPN protection, use a private network. Exploring the web on public Wi-Fi networks is very dangerous and opens up your traffic to unauthorized exposure. Using a private network helps maintain a secure connection and offers more resilience to external threats.
• Learn how different VPN split tunneling options work. For instance, inverse split tunneling only encrypts the traffic of selected apps, letting the rest access the internet directly. Any new app would have to be added to the VPN connection manually, leaving you exposed if you forget to do that or if an app is installed without your knowledge. For these reasons, we don’t recommend using inverse split tunneling on work devices.

Why use split tunneling?

Even when you factor in the risks, VPN split tunneling offers important advantages for network connection and efficiency.

• Conserving VPN bandwidth. Even the best corporate VPN can become congested during peak hours. If an organization’s VPN connection is metered, routing everything via paid VPN servers might quickly exhaust the company’s data plan and leave it paying through the nose. VPN split tunneling acts as a practical compromise between cost, accessibility, and security, allowing companies to provide secure remote access to their internal resources without overloading the IT infrastructure.
• Using LAN services. VPN encryption doesn’t always play nice with local area networks (LAN). In some cases, using a VPN outright blocks LAN connections to printers, scanners, and other hardware devices. With split tunneling, you can freely access local resources while retaining secure access to your organization’s remote servers. Some VPNs support split tunneling for LAN access by default.
• Supporting “anywhere operations.” VPN split tunneling offers flexibility to remote workers, allowing firms to hire the best talent regardless of their geographical location. Properly training employees on safe split tunneling practices lets them securely work from anywhere while maintaining their own private digital life.
• Enjoying better speed for gaming and streaming. Workplace benefits aside, VPN split tunneling also has a lot to offer to casual internet users. All VPNs slow down connection speed due to data encryption and rerouting — though the slowdown is usually imperceptible thanks to the fastest VPNs using modern VPN protocols. Nevertheless, this can lead to stream buffering or in-game lag. With a properly set up split tunnel, speed-hungry apps can enjoy direct access to the internet while the remaining online traffic is shielded by a VPN.

When should you not use VPN split tunneling?

Given the security risks it poses, it’s recommended to avoid using split tunneling in certain scenarios.

• When security is the top priority. If you’re working with highly sensitive information or if your company handles confidential data, preventing any security gaps is key. Using VPN split tunneling creates too many opportunities for users to accidentally or maliciously open up the system to critical cybersecurity threats.
• When you’re using public Wi-Fi networks. As discussed earlier, public Wi-Fi isn’t the safest option to navigate without secured connection. If a cybercriminal intercepts your direct traffic and your device is compromised, the apps and websites you access via the split tunnel can also be affected.
• When you need to maintain privacy. VPN split tunneling only encrypts the traffic you route through the VPN. If you accidentally mismanage which sites and apps you use via the tunnel and which you reach via a direct connection, your traffic might stop being private.
• When you access corporate or remote work environments. Using split tunneling can inadvertently allow malware to reach your device or expose sensitive corporate data if apps bypass the VPN. It also increases the risk of mixing personal and work traffic in ways that may compromise security.

How split tunneling works on NordVPN

With NordVPN, you can set up split tunnelling and reroute part of your online traffic outside the VPN connection. You can choose which apps and websites you want to access through the tunnel and which ones can bypass your VPN. Split tunnelling makes it easy to access sensitive information while you’re on the go, and flexible website allowlist management ensures you don’t let vulnerable pages slip through the cracks.

As one of the best VPN providers in the market, NordVPN lets you set up and manage VPN split tunneling on Windows, Android, and Android TV devices.