Security Exception while running sites using subdomain?

Question

I have 3 sites :

1. media.lmenaria.com -> Hosting Images
2. webservice.lmenaria.com -> Sending images url from database.
3. www.lmenaria.com -> Host Silverlight application and display images.

When I run page "http://www.lmenaria.com/silverlight.aspx". I am getting below exception. So what shpould I do ?

System.Security.SecurityException: Security error.
   at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
   at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
   at System.Net.Browser.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)   at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
   at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
   at System.Net.WebClient.OpenReadAsyncCallback(IAsyncResult result)

I think, my all sites runing at same domain, so I don't need crossdomain xmls. Please let me know how Can I fix it.

I have tried to put corssdoamin xml media.lmenaria.com,webservice.lmenaria.com both, and working fine, but only at
www.lmenaria.com not working.

We are downloading images using WebClient.

Thanks in advance, Laxmilal Menaria

Answer 1

Subdomains on the same domains are considered diffrent domain.
Consider the following scenario: http://www.myBank.com and http://api.myBank.com. In that scenario you want to enable cross domain calls to http://api.myBank.com and strictly block those off to http://www.myBank.com.

You will need to add a ClientAccessPolicy.xml to allow access to the subdomain that hosts the services from the other subdomains (even the WWW subdomain).

Sincerely,
-- Justin Angel