Presumably the application would have to be run by the root user.
I don't think there's anyway for an AIR app to request root permissions for a particular file operation.
I do the search in 4rum and found the solution:
+ use an external shell file to give permission
+ execute by Native Process
but when i run the command : "sudo chmod go+w /etc/hosts" in shell file, terminal ask me a password, how do i push the password from my AIR app to the shell file? (example : show a popup window to submit password, then assign it to NativeProcess).
var pwd = "my_p@$$w0Rd";
var pi = new air.NativeProcessStartupInfo();
... // add configuration for you proc
var proc = new air.NativeProcess(pi);
... // add stdout/stderr/exit handlers
proc.standardInput.writeUTFBytes(pwd + "\n");
*Disclaimer: I do not endorse hardcoding passwords! Just showing an example