The hackers on XDA-Developers never rest, and their latest exploit may have found a wide open hole in Windows Phone 8.1.
XDA hacker DJAmol has found that simply by replacing the contents of a trusted OEM app that has been moved to the SD card the app will inherit the privileges of the original app.
In this example, by moving Info and Settings to the SD card, then deleting its directly and creating a new directory with the same name, and a new app e.g. a registry editor, the 3rd party registry editor app will have all the access that the Info and Settings app has.
The hack is not only very simple to implement (simply using an app like Pocket File Manager) but should really have been foreseen by Microsoft.
As yet the hack has not escalated to a full interop unlock, as the apps which are allowed to be moved to the card (even Nokia’s apps) have limited access, but it appears it will only be a question of time before this leads to one.
Read more in the XDA-Developer thread here, where the hack is being expanded as we speak.