You can upload the ISO to the organization catalog in the HTML5 interface. To access the HTML5 interface, you need to add the organization's name to the link https://vcd.cloud4u.com/tenant/ as it is specified in the link to the FLASH interface, for example, from https://vcd.cloud4u.com/cloud/org/org-name you get https://vcd.cloud4u.com/tenant/org-name.
Switch to Libraries view mode
create new catalog (Catalogs/NEW)
On the Media & Other tab, press ADD, select the created catalog and ISO file to download