iPhone 4 jailbreak banks on browser exploit

Hackers have developed a browser-based tool able to jailbreak Apple's iPhone 4.

The tool, published on Sunday and available via JailbreakMe.com was developed by the iPhone Dev Team. It allows users of the smartphone to run apps other than those approved by Apple.

Unlike previous jailbreaking utilities, the latest application can be run via a mobile version of Safari. Previous tools often required a software download onto a computer paired with a iPhone.

The hack, which almost certainly relies on the exploitation of an unpatched mobile Safari vulnerability, works on iPhones, iPads and iPod Touches running iOS 4 and iOS 4.01. It doesn't work on iOS 4 beta.

Although the hack is simple to apply it's not without unwelcome side effects. Unconfirmed reports suggest FaceTime and MMS functionality can wind up broken on jailbroken devices.

And, of course, whether or not a iPhone 4 is jailbroken has no effect on its much publicised antenna problems.

The development follows last week's decision that jailbreaking iPhones was not a violation of US copyright technology protection laws. The Digital Millennium Copyright Act (DMCA) contains rules proscribing the circumvention of DRM controls, but iPhone jailbreaking and video remixing were designated as exceptions by the Copyright Office in response to a case brought by the Electronic Frontier Foundation.

Apple responded to the ruling by warning that jailbreaking its device will void any warranty protection. ®