Tungstenite allows remote attackers to cause a denial of service

The Tungstenite crate through 0.20.0 for Rust allows remote attackers to cause
a denial of service (minutes of CPU consumption) via an excessive length of an
HTTP header in a client handshake. The length affects both how many times a parse
is attempted (e.g., thousands of times) and the average amount of data for each
parse attempt (e.g., millions of bytes).