As detailed by Engadget, the glitch can be accomplished on any model locked iPhone running iOS 4.1. Users can access the handset's phone application by dialing a random number from the "Emergency Call" button on the iPhone lock screen, and quickly pressing the lock button after dialing that call.
Upon pressing the hardware lock button atop the iPhone, a user can then access the call history, voicemail and address book on the phone. The glitch works on the iPhone 3G, iPhone 3GS and iPhone 4.
Once in the phone application, neither the lock or home buttons work, and the handset can only be returned to the lock screen by attempting to place a call. However, users can also hold down the home button to access voice control and play music from the iPod application.
Selecting "share contact" and then choosing the camera icon also allows users to view the photo album on the iPhone without having properly unlocked the device with the secure passcode.
The report noted that the glitch is also functional in early beta builds of iOS 4.2. Apple's forthcoming software update for the iPhone, iPod touch and iPad is set for release sometime in November.