This week, Daniel Roesler published information on how the ISP assigned IP address can possibly be revealed even while using a VPN connection with Windows. This can be achieved by using the WebRTC implementation in Mozilla Firefox and Google Chrome in Windows, which allows sending packets bypassing the local routing table. Roesler provies a demonstration on his page at GitHub.
After examining this issue we can say the following:
First and foremost this only works if your browser is running with administrator rights. It goes without saying that if you are using a VPN to protect your anonymity you should not run your browser with escalated priviliges – this is generally not a good idea.
Secondly, as a Perfect Privacy user you can prevent this, by activating the firewall protection in the Perfect Privacy VPN Manager. Any setting will suffice to prevent WebRTC from bypassing the routing table.
Additionally there are several other methods to protect against this leak. Chrome users can install the WebRTC block and Firefox users can enter “about:config” in the address bar and set the value for the parameter media.peerconnection.enabled to false. Another option is to use a browser that does not support WebRTC.
In conclusion we recommend to never run your browser with administrator rights and if you are running Windows you should also make sure that the firewall protection in the client is activated for additional protection.
Your Perfect Privacy Team