If you want to use SMB folder sharing for vagrant on a windows machine, you will need to run the CLI as administrator and then provide the login and password. The problem is that MinTTY and Cygwin do not support the no-echo TTY mode.

To fix this I use this code snippet:

# Capture username and password for smb synced folders (Windows)
if OS.windows?
   puts "\e[36mDue to MinTTY and Cygwin not supporting the no-echo TTY mode"
   puts "it is necessary to request your account username and password"
   puts "at this stage in order to correctly setup SMB shared folders.\e[0m"
   puts

   if !parameters['smb_username']
      print "\e[35mEnter username:\e[0m "
      STDOUT.flush
      smb_username = STDIN.gets.chomp
   else
      puts "\e[32mUser name is already supplied in parameters.\e[0m"
      puts
      smb_username = parameters['smb_username']
   end

   if !parameters['smb_password']
      # 8m is the control code to hide characters
      print "\e[35mEnter password:\e[0m \e[0;8m"
      STDOUT.flush
      smb_password = STDIN.gets.chomp
      # 0m is the control code to reset formatting attributes
      puts "\e[0m"
      STDOUT.flush
   else
      puts "\e[32mUser password is already supplied in parameters.\e[0m"
      puts
      smb_password = parameters['smb_password']
   end
end