TunnelVision
TunnelVision is an attack that uses DHCP option 121 to set higher priority routes so that traffic does not go through the VPN.
Reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-3661
Status
Android
Android does not handle DHCP option 121 and is not affected.
Apple platforms
Update sing-box graphical client to 1.9.0-rc.16 or newer,
then enable includeAllNetworks in Settings — Packet Tunnel and you will be unaffected.
Note: when includeAllNetworks is enabled, the default TUN stack is changed to gvisor,
and the system and mixed stacks are not available.
Linux
Update sing-box to 1.9.0-rc.16 or newer, rules generated by auto-route are unaffected.
Windows
No solution yet.
Workarounds
- Don't connect to untrusted networks
- Relay untrusted network through another device
- Just ignore it