Apple iOS Jailbreak Follows Security Update

The iPhone Dev-Team has released a new jailbreak for Apple's iOS operating system.

The jailbreak, known as Redsn0w 0.9.6b4, was released Monday just hours after Apple released an update for iOS. Right now, the jailbreak is tethered on all recent devices, according to the Dev-Team blog.

"A tethered jailbreak means that each time your device loses battery power or needs to be rebooted, you must attach it to a PC or Mac to boot into the jailbroken state," the blog notes.

For those not looking for a jailbreak, the latest version of Apple's mobile operating system addresses more than 80 security flaws, including 27 affecting the WebKit browser engine. Several of the WebKit flaws could be exploited to cause arbitrary code execution, such as an invalid cast issue in WebKit's handling of CSS boxes that can be exploited if a victim visits malicious sites.

Among the other vulnerabilities addressed by the update is a heap buffer overflow issue in FreeType's handling of TrueType opcodes. The issue could be exploited by viewing a PDF file with maliciously crafted embedded fonts. If exploited successfully, it could enable attackers to execute code. The situation was fixed with improved bounds checking, Apple said.

Apple also fixed a memory corruption vulnerability in OfficeImport's handling of Excel files.

"Viewing a maliciously crafted Excel file may lead to an unexpected application termination or arbitrary code execution," according to Apple's advisory. "This issue is addressed through improved bounds checking. This issue was addressed on iPhones in iOS 4."

"It's critical that users of Apple's popular gadgets update their operating system as soon as possible," blogged Graham Cluley, senior technology consultant at Sophos. "Fixes ... include patches for the Web browser. Without these, users could be at risk when they visit booby-trapped Websites—code embedded on the Website could cause iOS applications to crash, or even plant and run malicious code on the device."

The update can be downloaded via iTunes for iPhone, iPad and iPod Touch users.