There were lots of iPhone users out there that did a little dance of joy when jailbreaking was tossed into the DMCA as fair use. This is a good thing for users who want the freedom to do with their handsets as they wish.
Not long after that, we saw the remote jailbreak surface from Dev-Team that makes it possible to jailbreak your iPhone by simply visiting the jailbreakme website. McAfee security sees some serious implications in the exploits used for the remote jailbreaking.
The remote jailbreak site takes advantage of an issue with the way the iOS on the iPhone handles compact font format data within a PDF file. The issue is exploited by the Jailbreakme website to take control of the device and jailbreak it. The rub according to McAfee is that while the Jailbreakme site isn't doing anything nefarious, what else could this flaw be used to execute. Apple has made no move to patch the flaw at this point according to McAfee. A hacker could use the same exploits to take over the device.