Friday, July 31, 2009, 10:45 am

iPhone SMS exploit patch expected this weekend

By Katie Marsal

A day after experts revealed a major text message-based security flaw in the iPhone, the BBC reports that Apple is expected to release a fix for the exploit through iTunes on Saturday.

The news that a patch is coming soon came from a spokesperson for O2, the iPhone's wireless carrier in the U.K. It was not immediately made clear whether a patch would be made available for all iPhone users, or just those in the U.K. The exploit also affects Google Android and Windows Mobile phones. Google has reportedly taken steps to fix the security hole.

Security researcher Charlie Miller, co-author of The Mac Hacker’s Handbook, demonstrated the hack Thursday at the Black Hat 2009 conference in Las Vegas. The attack takes advantage of a vulnerability in the phone’s short messaging service, or SMS, feature, allowing an outside party into the phone’s root access without the owner’s knowledge.

When the hack was first revealed by Miller early in July, Apple was expected to release a fix before the Black Hat conference, where he gave greater detail. But that fix never came before Miller's talk.

The exploit takes advantage of the fact that SMS can send binary code to a phone. That code is automatically processed without user interaction, and can be compiled from multiple messages, allowing larger programs to be sent to a phone. The exploit supposedly exposes the iPhone completely, giving hackers access to the camera, dialer, messaging and Safari. It occurs regardless of hardware revision or which version of the iPhone OS is running.

The technique involves sending only one unusual text character or else a series of "invisible" messages that confuse the phone and open the door to attack. Because users won't know whose messages to block in advance, there's little iPhone owners can do but to shut off the phone immediately if they suspect they're at risk -- a real problem as the trick could also be used to make an iPhone send more messages of its own.