The remote web server contains a 'crossdomain.xml' file.
The remote web server contains a cross-domain policy file. This is a simple XML file used by Adobe's Flash Player to allow access to data that resides outside the exact web domain from which a Flash movie file originated.
Review the contents of the policy file carefully. Improper policies, especially an unrestricted one with just '*', could allow for cross-site request forgery and cross-site scripting attacks against the web server.