View source for SandBox Security Model

[[OWASP Code Review Guide Table of Contents]]__TOC__

'''Flash player assigns SWF files to sandboxes based on their origin'''

'''Internet SWF files sandboxed based on origin domains'''
'''Domain:'''
- Any two SWF files can interact together within the same sandbox. 
- Explicit persmission is required to interact with objects in other sandboxes.

'''Local'''

'''local-with-filesystem (default)'''
- The file system can read from local files only

'''local-with-networking'''
- Interact with other local-with-networking SWF files

'''local-trusted'''
- Can read from Local files, communicate to any server and access any SWF file.


“The sandbox defines a limited space in which a Macromedia Flash movie
running within the Macromedia Flash Player is allowed to operate. Its primary
purpose is to ensure the integrity and security of the client’s machine, and as
well as security of any Macromedia Flash movies running in the player.”


Cross Domain Permissions:
A Macromedia Flash movie playing on a web browser is not allowed access that is outside the exact domain from which is originated.
This is defined in the cross-domain policy file crossdomain.xml.
Policty files are used by Flash to permit Flash to load data from servers other than its native domain.
If a SWF file wishes to communicate with remote servers it must be granted explicit permission:

 <cross-domain-policy> 
     <allow-access-from domain="example.domain.com"/>
 </cross-domain-policy>

The API call System.security.loadPolicyFile(url) loads a cross domain policy from a specified URL which may be different from the crossdomain.xml file


'''Accessing JavaScript:'''

A parameter called allowScriptAccess governs if the Flash object has access to external scripts
It can have three possible values: '''never, same domain, always'''

  <object id="flash007"> 
    <param name=movie value="bigmovie.swf">
    <embed AllowScriptAccess="'''always'''" name='flash007' src="bigmovie.swf"  type="application/x-shockwave-flash"> 
   </embed>
  </object>