New Apple iOS, OS X Flaws Pose Serious Risk

Researchers at Indiana University in Bloomington discovered multiple serious security vulnerabilities in Apple's iOS and OS X platforms that pose a risk to user passwords, authentication tokens, and other confidential data.

Apple was informed of the vulnerabilities in October 2014, but so far has not fully patched them. As a result, users of both OS X and iOS systems remain at risk of attack, the researchers say.

Apple did not immediately respond to a Dark Reading request for comment.

The vulnerabilities stem from the manner in which the two operating systems isolate applications that are installed on a system from each other. Poor app-to-app and app-to OS authentications in both OS X and iOS allow for different kinds of cross-application resource access attacks (XARA), the researchers said in a 13-page technical report released this week.

The Indiana University researchers, assisted by two others from Peking University and the Georgia Institute of Technology, described the vulnerabilities as high-impact security weaknesses. The flaws can be exploited to steal data like passwords for iCloud, email and bank accounts, notes and user contacts stored in Evernote, and photos in applications like WeChat, they warned.

“So far, little has been done to understand whether the construction of app isolation on Apple platforms is secure,” the researchers said. “We conducted the first study on the XARA risks of Apple’s isolation mechanisms, and discovered surprising security-critical vulnerabilities.”

Several cross-application resource-sharing mechanisms in both iOS and OS X including keychain, WebSocket, and Scheme, are not adequately protected either by the operating system nor the applications using them.

To take advantage of the flaws, an attacker would first need to upload a sandboxed malicious application to Apple App Store and have it approved. Though that might appear to be a challenging task, the researchers claimed they were able to upload proof-of-concept attack code to Apple’s application store and have it pass the company’s standards for approved applications. The apps were promptly removed from the store once they were approved, the report added.

In total, the researchers discovered four separate vulnerabilities in iOS and OS X. One of them is a password-stealing vulnerability in Apple’s Keychain credential management feature for securely storing passwords to applications and online services. A weakness in the access control mechanism within Keychain gives malicious applications a way to hijack another application’s Keychain entry, or to create a new Keychain entry for another application.

“If the targeted app is not present on the computer and the user subsequently installs the app, its credentials are stored on the keychain entry created by the malicious app,” Symantec said in its analysis of the XARA research report.

The second weakness exists in the manner in which the operating systems handle a unique identifier known as Bundle ID (BID) that is associated with each app container. The flaw basically gives attackers a way to break into containers by creating a malicious application that uses a BID belonging to another app.

The researchers described the third vulnerability as an inter-process communication interception issue in OS X and platforms like WebSocket that are used to establish connections between a Web server and a client PC. Symantec in its analysis says that would allow a malicious app to “claim the port used by a legitimate application and intercept data intended for it, such as passwords or other sensitive information.”

The fourth vulnerability, described as a scheme-hijacking flaw by the researchers, gives attackers a way to intercept authentication tokens and other data sent to a legitimate application.

“Most XARA risks are caused by the confusion about which party—the OS or the app develop--should be responsible for protecting an app’s resource,” says Luyi Xing, one of the researchers from Indiana University responsible for discovery. “Oftentimes, Apple thinks that the developer should do that but fails to make it clear to the developer,” he said in an email exchange with Dark Reading. The scheme hijacking issue on OS X is one example of this communication gap, he says.

“In some cases, even the means for the protection is not provided at the OS level,” he says, and the scheme-hijacking flaw is an example of that.

“The threat is severe because users’ passwords for banking, iCloud, email and everything could be stolen,” Xing says.

However, the researchers are working with Apple in trying to address the issues, he says. “We’re helping Apple fix the problems on Mac and iOS and enhancing vetting process of the app store.”