New TunnelVision Attack Allows Hijacking of VPN Traffic via DHCP Manipulation
May 09, 2024
Encryption / Data Privacy
Researchers have detailed a Virtual Private Network (VPN) bypass technique dubbed TunnelVision that allows threat actors to snoop on victim's network traffic by just being on the same local network. The "decloaking" method has been assigned the CVE identifier CVE-2024-3661 (CVSS score: 7.6). It impacts all operating systems that implement a DHCP client and has support for DHCP option 121 routes. At its core, TunnelVision involves the routing of traffic without encryption through a VPN by means of an attacker-configured DHCP server using the classless static route option 121 to set a route on the VPN user's routing table . It also stems from the fact the DHCP protocol, by design, does not authenticate such option messages, thus exposing them to manipulation. DHCP is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as ...
