We have recently disclosed a new vulnerability to the Android Security Team. The vulnerability affected many apps, including Settings (the one that is found on every Android device), Gmail, Google Now, DropBox and Evernote. To be more accurate, any App which extended the PreferenceActivity class using an exported activity was automatically vulnerable. A patch has been provided in Android KitKat. If you wondered why your code is now broken, it is due to the Android KitKat patch which requires applications to override the new method, PreferenceActivity.isValidFragment which has been added to the Android Framework.

Important links:
1. Blog post: http://ibm.co/1bAA8kF
2. Whitepaper: http://ibm.co/IDm2Es