Skip Links

Apple bans researcher for app exposing iOS security flaw

Flaw lets malware run on iPhones, iPads

By , Network World
November 08, 2011 12:00 PM ET

Network World - Apple has banned well-known security researcher Charlie Miller from its developer program, for creating an apparently benign iOS app that was actually designed to exploit a security flaw he had uncovered in the firmware.

Within hours of talking about the exploit with Forbes' security reporter Andy Greenberg, who published the details, Miller received an email from Apple: "This letter serves as notice of termination of the iOS Developer Program License Agreement ... between you and Apple. Effective immediately."

IN PICTURES: Security Industry All-Stars

Based on Greenberg's follow-up story, Apple was clearly within its rights to do so. Miller created a proof-of-concept application to demonstrate the security flaw and how it could be exploited by malicious code. He then hid it inside an apparently legitimate stock ticker program, an action that, according to Apple, "violated the developer agreement that forbid[s] him to 'hide, misrepresent or obscure' any part of his app," Greenberg wrote.

He quoted Miller, who works for security consultancy Acuvant, "I'm mad. I report bugs to them all the time. Being part of the developer program helps me do that. They're hurting themselves, and making my life harder."

Miller, a former National Security Agency staffer, is a well-known "white hat" hacker (he made Network World's recent list of "Security All Stars"), with expertise in Apple's Mac OS X and iOS platforms, including the Safari browser, and in Android. Miller "has found and reported dozens of bugs to Apple in the last few years," Greenberg noted. Miller reported the latest one barely three weeks ago, and it was Greenberg's public account of it yesterday, in advance of a planned public presentation by Miller next week, that got the researcher kicked out of the developer program.

The vulnerability is a fascinating exercise in information security sleuthing. Miller uncovered a flaw introduced in Apple's restrictions on code signing on iOS devices. Code signing is a process by which only Apple-approved commands run in device memory, according to Greenberg's account.

Miller began to suspect a flaw when Apple released iOS 4.3 in March. He realized that to boost the speed of the mobile Safari browser, Apple for the first time had allowed javascript code from a website to run at a deeper level in memory. This entailed creating a security exception, allowing the browser to run unapproved code. According to Greenberg's story, Apple created other security restrictions to block untrusted websites from exploiting this exception, so that only the browser could make use of it.

Miller wasn't the only one to notice that Apple had done something different with Safari in iOS 4.3, but many didn't understand what was actually happening. Various news sites and bloggers claimed that Web apps running outside of Safari, and its new Nitro javascript engine, were slower. Some suggested that Apple was deliberately slowing them down to make Web apps less attractive than native ones.

Our Commenting Policies
Latest News
rssRss Feed
View more Latest News