No. Flex/Flash Player/browser has strong security restrictions that prevent access to any client assets.
Wouldn't it be secure enough to ask the user whether she or he wants to allow scanning, just like it is done with the webcam or with the microphone? Does scanning involve more security-related issues than acquiring data from the webcam? I do not see them.
In other words: I would love to see this capability in Flex .
I doubt it'll be happening pure Flex (i.e. inside a browser) at any time in the near future.
Now for an AIR/Flex application that's a different story. I still don't see AIR support for doing this type of thing but you can most definitely make a call to Java which I'd imagine can handle this requirement... nowadays it's usually the norm that "Java can do it".