1 min read

Link: Novel attack against virtually all VPN apps neuters their entire purpose

The attack allows some or all traffic to be routed through the unencrypted tunnel. In either case, the VPN application will report that all data is being sent through the protected connection. Any traffic that’s diverted away from this tunnel will not be encrypted by the VPN and the Internet IP address viewable by the remote user will belong to the network the VPN user is connected to, rather than one designated by the VPN app. Interestingly, Android is the only operating system that fully immunizes VPN apps from the attack because it doesn't implement option 121. For all other OSes, there are no complete fixes. When apps run on Linux there’s a setting that minimizes the effects, but even then TunnelVision can be used to exploit a side channel that can be used to de-anonymize destination traffic and perform targeted denial-of-service attacks. Network firewalls can also be configured to deny inbound and outbound traffic to and from the physical interface. This remedy is problematic for two reasons: (1) a VPN user connecting to an untrusted network has no ability to control the firewall and (2) it opens the same side channel present with the Linux mitigation. The most effective fixes are to run the VPN inside of a virtual machine whose network adapter isn’t in bridged mode or to connect the VPN to the Internet through the Wi-Fi network of a cellular device. #


Yoooo, this is a quick note on a link that made me go, WTF? Find all past links here.