About Flex access to remote data sources

For security reasons, applications running in Flash Player on a client computer can only access remote data sources if one of the following conditions is met:

Your application's compiled SWF file is in the same domain as the remote data source.
You use a proxy and your SWF file is on the same server as the proxy.
Adobe Flex Data Services provides a complete proxy management system for Flex applications. You can also create a simple proxy service using a web scripting language such as ColdFusion, JSP, PHP, or ASP. For more information on creating your own proxy, see the following TechNote on the Adobe website at www.adobe.com/go/16520#proxy.

A crossdomain.xml (cross-domain policy) file is installed on the web server hosting the data source.
The crossdomain.xml file permits SWF files in other domains to access the data source. For more information on configuring crossdomain.xml files, see the following TechNote on the Adobe website at www.adobe.com/go/14213.