Does iOS Need Antivirus Protection?

By now, security-conscious IT pros know about the new and improved version of the iOS jailbreaking software, jailbreakme, now with iPad 2 support. It ingeniously exploits a flaw in the iOS PDF display code to, via a buffer overrun attack, load jailbreak code into the root file system of the device. Once rebooted, the hacked code injects itself into the device's startup sequence using the video frame buffer as its temporary scratch memory.

What makes this exploit so nefarious is not only its device-independence (it works on everything from the original iPhone and iPad Touch to the latest iPad 2), but that it uses innocuous-looking PDF files, delivered via the browser using Safari's built-in PDF viewer, as its distribution method. While jailbreakers generally know what they're getting into, the same technique could be used more deviously by those with less wholesome intentions to deliver "modified" PDF files via obfuscated URL shortening and a Twitter or Facebook feed. While the specific PDF vulnerability has not been publicly identified, and the current exploit isn't known to have a malicious payload, the technique could easily be used for more nefarious purposes than jailbreaking.