Hi Eric, Consider the case where a company has servers protected by a gateway firewall. The servers should not be visible from the public Internet at all - only from within the corporate network. Now someone downloads a Flash movie onto a workstation inside the firewall. If Flash allowed you to try to connect to any IP/Port, regardless of where the movie came from, then the Flash movie could act as a behind-the-firewall proxy to try to retrieve information that should never leave the corporation. If Flash allowed that it would banned in more places than it already is. Yours truly, -Brian
Eric Raymond wrote: >I must be missing something, but I'm a bit confused as to the design >of the Flash Security Model and crossdomain.xml. > >My main question is who is this model intended to protect? > >As I undestand it, this protects third party servers from disclosing >their "data" to flash clients. That is, if you do not have a cross >domain file on a third party server, a flash program cannot access the >data. But, any other program (e.g. ,a web browser, socket program, >etc) could easily access this data. It's up to the client to recuse >itself (and only flash clients recuse themselves). It would seem for >a server to protect itself, it would have to enforce the protection, >not the client. > >My expectation was that this was more like a Java sandbox which >prevented a program from accessing other sites for the protection of >the client, not the server. In such a scheme one might expect the >crossdomain.xml file to be controlled by the server which served the >flash application (not the 3rd party server) ... a chain of trust. >If it's controlled by the 3rd party, then there's not a huge amount of >protection. > >So I can't see any benefit of letting the thrid party server be in >control of this file. If the crossdmain.xml file is to protect the >server, then it misses the case where non-flash clients can access the >server. If it is to protect the client from a malicious thrid party, >the third party can simply add a crossdomain.xml file to their site. > >Perhaps this is to avoid DOS'ing a third party site from a flash app, >but attempting to grab the crossdomain.xml file could be a form of >attack (although arguably less intensive). > >So what am I missing here? > >Perhaps there are use cases that I don't see that this model affords >protection either to the client or the server. > > > > > > >-- >Flexcoders Mailing List >FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt >Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com >Yahoo! Groups Links > > > > > > > > -- ______________________________________________________________________ Brian Lesser Assistant Director, Teaching and Technology Support Computing and Communications Services Ryerson University 350 Victoria St. Toronto, Ontario Phone: (416) 979-5000 ext. 6835 M5B 2K3 Fax: (416) 979-5220 Office: AB48D E-mail: [EMAIL PROTECTED] (Enter through LB66) Web: http://www.ryerson.ca/~blesser ______________________________________________________________________ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/flexcoders/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
