The problem with doing -- and not doing -- an iPhone jailbreak

Jailbreak your iPhone or stay off the Internet, say security researchers.

Code that exploits two iPhone flaws to allow people to jailbreak their devices could, ironically, force security-conscious users to use the vulnerabilities to jailbreak their own iPhones and apply a third-party patch.

Wednesday, an iPhone hacker known as Comex updated a site dedicated to jailbreaking iPhones with code that uses two previously unknown vulnerabilities to gain root access to users' devices and jailbreak them, allowing non-App store code to run on Apple's platform. By visiting the site, users who want to jailbreak their phones can install the custom operating system on iPhones, iPads and the iPod Touch in less than 20 seconds, security firm Websense writes in a blog post.

Also see: Mobile phone security dos and don'ts

"And it's very, very simple and works flawlessly," Patrik Runald, a security researcher with Websense, writes in the blog post. "It doesn't crash your browser, and it even looks and feels like a regular App Store installation. Very slick but also very dangerous."

Clicking on the "Free" button on the jailbreak site downloads a PDF file containing an exploit that takes advantage of a vulnerability in the built-in PDF reader's handling of a certain font type. The program is "dangerous," argues Runald, because the exploit could be reverse engineered and turned into an attack.

"It wouldn't be hard for a malicious attacker to reverse engineer how the jailbreak works and create something similar that doesn't require the user to click on (a button) and silently installs malicious code on your iOS device, either through the browser or via an email attachment," he writes.

Also see: Your iPhone's dirty little secret

While cybercriminals have not yet adapted the exploit to create infected sites that can install malicious code, the risk exists, say researchers. Apple is working on a fix for the issue, but did not specify timing.

"Apple takes security very seriously," the spokesperson said on Friday. "We have said that a fix will be available."

While the patch will likely come before the next major iOS update, version 5.0, security-conscious iPhone users have little recourse but to install a third-party patch, says Charlie Miller, a security consultant with Accuvant. To do that, they would have to jailbreak their phone first.

"If you jailbreak the phone -- I'm serious -- if you jailbreak and you go to Cydia, the app store for jailbroken phones, there is a program that you can patch the phone with," he says.

Also see: 7 steps to stronger enterprise iPhone security

Jailbreaking the iPhone significantly weakens the security measures instituted by Apple in the iOS. Users could fix the current flaw, but be more vulnerable for other issues.

Unfortunately, the user has to decide which situation is more dangerous, says Miller. For the most part, Apple has done a good job of security with its iOS, but because of its control over the platform, users cannot install third-party security software, which could have otherwise eliminated issues posed by the current flaws.

The vulnerabilities exist in the development versions of the iOS 5.0, according to a post on a blog dedicated to iPhone development.

"The holes still exist in the iOS5 betas, but theyll almost certainly be fixed by the time iOS5 is public," the post stated. "If history repeats itself though, there will be more holes and exploits."

Copyright © 2011 IDG Communications, Inc.

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