SSHD allows unencrypted sessions regardless of server policy
15 Dec. 1999
Summary
In the SSH1 protocol, during connection setup, the server sends a list of supported ciphers to the client. This list represents the server policy and includes the ciphers the server is willing to accept. Usually the client chooses one cipher from this list and sends its choice back to the server.
However, in all these implementations, the server does not check whether the cipher chosen by the client is included in the list of previously offered ciphers, making it possible for a remote client to choose a cipher level of 'none' - effectively rendering SSH into an "expensive" telnet client.
