Apple Releases iPhone OS 3.0.1 to Close SMS-Based Security Hole

Responding to a dangerous security exploit unveiled this week, Apple released an update to its iPhone operating system Thursday to patch the security hole.

iPhone OS has just become available for the iPhone, iPhone 3G and iPhone 3GS handsets. The update is between 230 and 300 megabytes and appears to exclusively fix the reported SMS exploit.

According to AppleInsider, 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.

The exploit takes advantage of the fact that SMS can send binary code to a phone which is then 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, allowing 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. Given that users won’t know which 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. Once exploited, the trick could also be used to make an iPhone send additional messages of its own, thereby spreading the problem.

To install the new iPhone OS firmware, simply connect your iPhone to your Mac or PC, open iTunes, select the iPhone in the device window and tell it to check for an update. The process will complete on its own.

If you’ve tried the new firmware, let us know what you make of it in the comments or forums.