VTun-ng is a Virtual Tunnel over TCP/IP network. In versions 3.0.17 and below, failure to initialize encryption modules might cause reversion to plaintext due to insufficient error handling. The bug was first introduced in VTun-ng version 3.0.12. This is fixed in version 3.0.18. To workaround this issue, avoid blowfish-256.
https://github.com/leakingmemory/vtun-ng/security/advisories/GHSA-m3jc-27c6-2wrf
https://github.com/leakingmemory/vtun-ng/commit/8c63982b6c487c52db1d56ab94c266f0bc857140