WebRTC (Web Real-Time Communication) is a technology that allows web browsers and mobile applications to make voice calls, video chat, and P2P file sharing without the need for external plugins. It allows direct communication between peers, meaning data is transmitted directly between users without going through an intermediary server.
A VPN (Virtual Private Network) is a service that encrypts internet traffic and masks a user’s IP address by routing it through an external server run by the VPN provider. This prevents the user’s ISP or any external parties from monitoring their online activity or identifying their real location.
Using a VPN is important for online privacy and security, as it hides the user’s true IP address and encrypts their traffic to prevent snooping or blocking. However, WebRTC can sometimes bypass VPN encryption and reveal a user’s real IP address in what is known as a WebRTC leak. This reduces the effectiveness of the VPN in protecting privacy.
This article will discuss what WebRTC leaks are, the risks they pose to anonymity online, how to prevent them, alternatives to VPNs for security, and which VPNs researchers have found to be vulnerable to leaking real IP addresses through WebRTC.
II. WebRTC Leaks and VPN
WebRTC leak refers to the unencrypted leakage of a user’s real IP address during WebRTC communications, even when they are connected to a VPN service.
Since WebRTC allows direct communication between browsers, the VPN tunnel can sometimes be bypassed. The WebRTC protocols can reveal the user’s local network address, rather than the VPN IP address they are supposed to be using.
This completely compromises the anonymity and privacy a VPN is meant to provide. With the real IP exposed, the user’s ISP and sites they communicate with are able to identify their true location and monitor their activity beyond the VPN encryption.
Disabling WebRTC altogether would prevent this issue, but isn’t always practical since many sites depend on WebRTC for communications and video chat functions. Fortunately, there are methods available to selectively block WebRTC leak vulnerabilities while still allowing necessary WebRTC traffic.
III. Preventing WebRTC Leaks
There are a few methods users and VPN services can implement to prevent the leakage of real IP addresses through WebRTC:
- Use a WebRTC Blocking Browser Extension
Extensions like WebRTC Leak Prevent and uBlock Origin can be installed on Chrome, Firefox, and Opera to blacklist certain WebRTC connections and prevent leak vulnerabilities. This allows necessary WebRTC traffic while sealing leaks.
- Perform a WebRTC Leak Test
Sites like IPLeak.net and BrowserLeaks.com will perform automated WebRTC leak tests from the browser. This checks if the VPN IP address or real address is exposed, letting users confirm the VPN protects against leaks before transmitting sensitive traffic.
- Disable WebRTC on the Browser
In Chrome and Firefox browsers, simply navigating to chrome://settings/content/webRTC or about:config and setting “media.peerconnection.enabled” to FALSE will disable WebRTC. This is effective but disables all WebRTC functionality, impacting sites dependent on WebRTC.
IV. Alternatives to VPN for Online Privacy & Security
While VPNs are popular, there are emerging alternative technologies that also have unique advantages:
- Residential Proxies & Protected Proxies
Proxies act as an intermediary that sites see instead of users’ real IP addresses, providing an additional layer of protection. Residential proxies use real residential IP addresses, making activity appear legitimate and circumventing blocks.
- Modern Censorship Bypass Technologies
Technologies like V2Ray, XRay, Hysteria, and Cloak bypass firewalls and overcome censorship without needing to trust a VPN provider with seeing all traffic. protocols like XTLS also provide encryption with less overhead.
These can provide practical alternatives to VPNs for certain threat models. However, VPNs still have unique advantages regarding holistic traffic tunneling and encryption, remaining the preferred option for many.
V. VPN Services Found to Leak IPs via WebRTC
Unfortunately, many major VPN providers have been found vulnerable to WebRTC IP leaks in research conducted by vpnMentor:
ProtonVPN – Researchers found that ProtonVPN’s native app leaks IPs even when WebRTC blocking is enabled within the settings. WebRTC leaks were also found in browsers while connected to ProtonVPN servers.
NordVPN – NordVPN claims WebRTC leaks are prevented, but researchers detected WebRTC leaks on a Linux machine when conducting an automated IP leak test via web browser.
Surfshark – Surfshark also did not protect against WebRTC leaks on Linux systems. Researchers found the WebRTC leak exposed the real public IP rather than the VPN IP address.
Hotspot Shield – Hotspot Shield similarly failed testing on Linux systems, allowing WebRTC IP leaks even with the browser extension installed and activated.
BufferedVPN – BufferedVPN claims they ensure no sensitive data leaks occur, but researchers demonstrated WebRTC leaks are still possible and expose the real IP address.
Overall, it seems the majority of popular commercial VPN providers still demonstrate vulnerabilities to IP exposures via WebRTC, reducing privacy protections. More improvement is needed within the VPN industry to address these risks. Users concerned with preventing WebRTC leaks may consider more privacy-focused open source VPN solutions instead.
WebRTC leaks pose a concerning vulnerability that can bypass VPN encryption tunnels and expose the real IP address, compromising privacy and security online. Fortunately, there are methods users and VPN providers can implement to detect and prevent WebRTC leaks proactively, such as through browser extensions, leak testing sites, and disabling WebRTC when not needed.
More transparency, auditing, and adoption of leak prevention measures is still required in the commercial VPN industry to protect users. For the highest degree of assurance, users may consider more open source VPN projects focused intently on privacy. As WebRTC usage rises, addressing these leaks will only grow in importance for internet anonymity overall.