{"schemaVersion":3,"id":"CVE-2020-15133","aliases":["UBUNTU-CVE-2020-15133","DEBIAN-CVE-2020-15133","GHSA-2v5c-755p-p4gv"],"status":"published","duplicateOf":null,"title":"Missing TLS certificate verification in Faye Websocket","description":"In faye-websocket before version 0.11.0, there is a lack of certification validation in TLS handshakes. The `Faye::WebSocket::Client` class uses the `EM::Connection#start_tls` method in EventMachine to implement the TLS handshake whenever a `wss:` URL is used for the connection. This method does not implement certificate verification by default, meaning that it does not check that the server presents a valid and trusted TLS certificate for the expected hostname. That means that any `wss:` connection made using this library is vulnerable to a man-in-the-middle attack, since it does not confirm the identity of the server it is connected to. For further background information on this issue, please see the referenced GitHub Advisory. 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