Hi,
The crossdomain.xml file grants a web client the required permission to handle data across multiple domains.
When clients request content hosted on a particular source domain and that content make requests directed towards a domain other than its own, the remote domain needs to host a cross-domain policy file that grants access to the source domain, allowing the client to continue the transaction.
To know the detailed information about crossdomain.xml, please refer the link below. Going through this link below will help you in understanding - why do you require a crossdomain.xml file and example uses cases of using crossdomain.xml file.
Setting crossdomain.xml file for HTTP streaming | Adobe Developer Connection
Here is the link for video session. It discusses secure ActionScript coding for cross-domain policy files, and how they determine the way data is shared among websites across different domains :
Cross-domain Policy Files | How to Develop Secure Flash Platform Apps | Adobe TV
Here is a community blog link that may help you in implementation:
Adobe CQ/Adobe AEM: How to implement robots.txt / sitemap.xml / crossdomain.xml in Adobe CQ / AEM
We hope this information helps!
Regards,
TechAspect Solutions
