find-my-way: DDoS with HTTP2

Impact

Remotely triggerable DoS in find-my-way when it is used with Node's HTTP/2 server.

The short version is that lookup() passes req.method into find(), and find() indexes this.trees[method]. Since this.trees is a normal object, HTTP/2 method values like constructor, toString, or __proto__ can resolve inherited object properties instead of returning undefined. The code then treats that value like a router node and crashes when it reaches currentNode.prefix.length.

Patches

Upgrade to v9.7.0.

Workarounds

Do not use find-my-way with HTTP/2 servers, or validate that the http method is valid beforehand.