Facebook and MySpace Backdoors Found, Fixed

jamie writes with news of a Facebook app developer who found a significant security hole while he was trying to get around function limitations for his application. Quoting: "Luckily — just with browser AJAX requests — a flash application hosted on domain X is unable to open a file on domain Y. If this would be possible, domain X [would be] able to access content on domain Y, and when the user is logged in on domain Y retrieve and post back any personal data. In certain cases this could limit a Flash application's capabilities. ... To resolve such issues, Adobe (Flash's developers) introduced a 'crossdomain.xml' file which could allow certain domains to access another domain, leading to cross-domain access by certain or all domains. While indeed Facebook locked the front door from any non-Facebook domain access via Flash, a simple subdomain change allowed any flash application (domain="*") to access its domain data." He found a similar problem in MySpace's crossdomain.xml. Both sites were notified, and they have implemented fixes.

Comments

Re:Huh.

[girlintraining]

I wonder how many people figured this out and didn't report it.

They didn't need to figure it out... Facebook lets people suck all that data out by making a game about vampires, pirates, farming, or god only knows whatever else is out there. Why go through the back door when the front door is already open and a welcome mat thrown out?