A vulnerability was found in NodeJS, where the IsAllowedHost check can be easily bypassed because IsIPAddress does not properly check if an IP address is invalid or not. When an invalid IPv4 address is provided (for instance, 10.0.2.555 is provided), browsers (such as Firefox) will make DNS requests to the DNS server. This issue provides a vector for an attacker-controlled DNS server or a Man-in-the-middle attack (MITM) who can spoof DNS responses to perform a rebinding attack and then connect to the WebSocket debugger allowing for arbitrary code execution on the target system.Read More