The Apple iPhone’s Safari web browser has a special feature that allows the user to dial any phone number displayed on a web page simply by tapping the number. SPI Labs has discovered that this feature can be exploited by attackers to perform various attacks, including:
* Redirecting phone calls placed by the user to different phone numbers of the attacker’s choosing
* Tracking phone calls placed by the user
* Manipulating the phone to place a call without the user accepting the confirmation dialog
* Placing the phone into an infinite loop of attempting calls, through which the only escape is to turn off the phone
* Preventing the phone from dialing
