Feeds

Apple kills code-signing bug that threatened iPhone users

Hacker who discovered it remains excommunicated

The Power of One eBook: Top reasons to choose HP BladeSystem

Apple has patched a serious bug in iPhones and iPads that allowed attackers to embed secret payloads in iTunes App Store offerings that were never approved during the official submission process.

Charlie Miller, who is principal research consultant at security firm Accuvant, was kicked out of the iOS developer program on Tuesday after demonstrating the danger posed by the weakness. The InstaStock title that he wrote and was accepted into the app store in September billed itself as nothing more than a program to track the share prices of publicly traded companies. But behind the scenes, it bypassed protections built into iOS devices that prevent code from running on them, unless it's signed by Apple's official cryptographic seal.

As a result, InstaStock allowed Miller, who is the other coauthor of The Mac Hacker's Handbook, to surreptitiously spy on anyone who installed the app. Just hours after he disclosed the secret functionality – and the bug that made it possible – Apple excommunicated him from the developer program, making him ineligible to test the security of new products before they are released to the public.

On Thursday, about 48 hours after Miller exposed the threat, Apple said it had closed the security hole in iOS 5.0.1.

“A logic error existed in the mmap system call's checking of valid flag combinations,” the advisory said. “This issue may lead to a bypass of codesigning checks.” The threat had existed since the release of iOS 4.3.

Code signing represents a significant barrier to getting malicious apps on iPhones and iPads that haven't been jailbroken. It prevents code from running on the devices unless it has been digitally signed by Apple officials, and it also stops developers from modifying the app after the fact. It is perhaps the single biggest security distinction between iOS and Google's rival Android operating system.

Miller was able to circumvent code signing after he discovered an exception that was introduced in iOS 4.3 that, for the first time, created a small region in iPhones and iPads where unsigned code downloaded from the internet could be executed. The exception was designed to improve the performance of Safari by allowing it to do just-in-time compiling.

Thursday's iOS update also includes fixes for at least four other security threats, including a flaw that allowed locked iPad 2 devices to be opened without entering a passcode. ®

Designing a Defense for Mobile Applications

More from The Register

next story
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
Four fake Google haxbots hit YOUR WEBSITE every day
Goog the perfect ruse to slip into SEO orfice
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.