Remember that PDF exploit from last year that JailbreakMe 2.0 was using to unlock your iPhone with just a few taps? Well, Apple patched it. And now it's apparently back. According to the Wall Street Journal, Apple acknowledged the exploit, and is working on an update at this very moment. In addition to the JailbreakMe 3.0 hack that came to light last week, the hole can also be used for some not-so-noble efforts, like grabbing your contacts database,
