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, accessing saved passwords, or activating your iPad or iPhone's built-in camera. And nobody wants that. For one reason or another, German authorities have taken the lead on encouraging Apple to investigate, and have also warned all users to avoid opening PDF docs from untrusted sources. And we're happy to echo that rather solid advice, given the implications. Ironically, JailbreakMe includes a patch for the very hole that allows it to function in the first place, so if you're terrified that rogue PDFs will take over your devices, that's an option to consider in the meantime.