Apple released a security update Thursday to address a series of flaws attackers could exploit to launch malicious code, trigger a denial-of-service or access sensitive information. In what some consider payback on Apple's part against the hacking community, the update renders most unlocked iPhones temporarily useless.
An input validation issue in the iPhone's Bluetooth server. By sending maliciously-crafted Service Discovery Protocol (SDP) packets to an iPhone with Bluetooth enabled, an attacker may trigger the issue, which may lead to unexpected application termination or arbitrary code execution, Apple said. The update fixes the issue by performing additional validation of SDP packets.
When Mail is configured to use SSL for incoming and outgoing connections, it does not warn the user when the identity of the mail server has changed or cannot be trusted. "An attacker capable of intercepting the connection may be able to impersonate the user's mail server and obtain the user's email credentials or other sensitive information," Apple said. "This update addresses the issue by properly warning when the identity of the remote mail server has changed."
Mail supports telephone ("tel:") links to dial phone numbers. By enticing a user to follow a telephone link in a mail message, Apple said, an attacker can cause iPhone to place a call without user confirmation. The update addresses the issue by providing a confirmation window before dialing a phone number via a telephone link in Mail.
A design issue in Safari allows a Web page to read the URL that is currently being viewed in its parent window. "By enticing a user to visit a maliciously crafted Web page, an attacker may be able to obtain the URL of an unrelated page," Apple said. "This update addresses the issue through an improved cross-domain security check."
Safari supports telephone ("tel:") links to dial phone numbers. When a telephone link is selected, Apple said, Safari will confirm that the number should be dialed. A maliciously crafted telephone link may cause a different number to be displayed during confirmation than the one actually dialed. Exiting Safari during the confirmation process may result in unintentional confirmation. This update addresses the issue by properly displaying the number that will be dialed and requiring confirmation for telephone links.
The security update blocks some iPhones that have been unlocked. Before the update downloads, Apple warns iPhone owners with a message: "Warning: Apple has discovered that some of the unauthorized unlocking programs available on the Internet may cause irreparable damage to the iPhone's software," the message read. "If you have modified your iPhone's software, applying this software update may result in your iPhone becoming permanently inoperable."