GHSA-VP88-798V-H67F rustls: ECH rejection can expose buffered application data to authenticated outer server before `ech_required` alert

In rustls 0.23.44 and 0.23.45, application data that a client buffers before the handshake completes is sent to the server even when the server rejects Encrypted Client Hello ECH. When the server rejects ECH, the client completes the handshake with the outer ClientHello and authenticates the serv...

rustls: ECH rejection can expose buffered application data to authenticated outer server before `ech_required` alert

In rustls 0.23.44 and 0.23.45, application data that a client buffers before the handshake completes is sent to the server even when the server rejects Encrypted Client Hello ECH. When the server rejects ECH, the client completes the handshake with the outer ClientHello and authenticates the serv...