TrustTunnel is an open-source VPN protocol with a server-side request forgery and and private network restriction bypass in versions prior to 0.9.114. In `tcp_forwarder.rs`, SSRF protection for `allow_private_network_connections = false` was only applied in the `TcpDestination::HostName(peer)` path. The `TcpDestination::Address(peer) => peer` path proceeded to `TcpStream::connect()` without equivalent checks (for example `is_global_ip`, `is_loopback`), allowing loopback/private targets to be reached by supplying a numeric IP. The vulnerability is fixed in version 0.9.114.
https://github.com/TrustTunnel/TrustTunnel/security/advisories/GHSA-hgr9-frvw-5r76
https://github.com/TrustTunnel/TrustTunnel/commit/734bb5cf103b72390a95c853cbf91e699cc01bc0