CuteFTP uses passive mode to initiate all connections while the server only waits for requests. When active, this feature helps avoid conflicts with the security system. Passive mode is active by default. If your transfers are working fine, you do not need to change this setting.
To enable or disable PASV mode
Click File > Site Manager.
Click the site you want to modify, then click Edit.
In the Data connection box, do one of the following:
To enable PASV mode, select the Use PASV mode check box.
To disable PASV mode, clear the Use PASV mode check box.