The below ppt shows the things to do.. follow them for secure flex app.
flex-security.ppt [click this to view]
- ¬MXML tags with security restrictions
- ¬Disabling viewSourceURL
- ¬Remove sensitive information from SWF files
- ¬Input validation
- ¬ActionScript
- ¬Using passwords.
These were the topics covered in this ppt [tutorials]very use full.

