Caido is a web security auditing toolkit. Prior to 0.55.0, Caido blocks non whitelisted domains to reach out through the 8080 port, and shows Host/IP is not allowed to connect to Caido on all endpoints. But this is bypassable by injecting a X-Forwarded-Host: 127.0.0.1:8080 header. This vulnerability is fixed in 0.55.0.