Android flaw puts personal data at risk for millions

Nearly half of Android devices are vulnerable to an attack that could replace a legitimate app with malicious software that can collect sensitive data from a phone.

Google, Samsung and Amazon have released patches for their devices, but 49.5 percent of Android users are still vulnerable, according to Palo Alto Networks, which discovered the problem. Google said it has not detected attempts to exploit the flaw.

A malicious application installed using the vulnerability, called "Android Installer Hijacking," would have full access to a device, including data such as usernames and passwords, wrote Zhi Xu, a senior staff engineer with Palo Alto.

The company wrote two exploits that take advantage of the flaw, which involves how APKs (Android application packages) are installed.

The vulnerability only affects applications that are installed from a third-party app store. Security experts generally recommend using caution when downloading apps from those sources.

Apps downloaded from third parties place their APK installation files in a device's unprotected local storage, such as an SD card, Xu wrote. From there, a system application called PackageInstaller finishes the installation. The flaw allows an APK file to be modified or replaced during installation without anyone knowing.

An attack would work like this: A user downloads what appears to be a legitimate application. The application asks for certain permissions on the device. During that process, Palo Alto found it was possible to swap or modify the APK file in the background because the PackageInstaller fails to verify it, Xu wrote.

After clicking the install button, "the PackageInstaller can actually install a different app with an entirely different set of permissions," he wrote.

Android devices do not need to be rooted for the attack to work, although rooting does make devices more vulnerable.

When the flaw was discovered, in January 2014, close to 90 percent of all Android devices were affected. That has since dropped to 49.5 percent, but many devices have not been patched.

Palo Alto's exploits were successful against Android versions 2.3, 4.0.3 to 4.0.4, 4.1.x, and 4.2.x. The 4.4 version of Android fixes the issue. Some Android 4.3 devices may still be affected, however, since some manufacturers have not patched yet, Xu wrote.

Google has published a patch here, and Amazon recommends downloading the latest version of the Amazon AppStore, which will update its Fire devices, Xu wrote.

Palo Alto has also developed an Android app that will detect if a device is still vulnerable.

Researcher points out critical Samsung Android phone vulnerabilities

Tired of waiting for Samsung to fix a string of critical flaws in their smartphones running Android, Italian security researcher Roberto Paleari has decided to inform the public about the seriousness of the matter and maybe make

matter and maybe make the company pick up the pace.



Mindful of the danger that the vulnerabilities present to the users if they are exploited by malicious individuals, he decided not to share any technical details, but to just give a broad overview of what their misuse would allow:

•a silent installation of highly-privileged applications with no user interaction
•SMS sending and changing of various phone settings without the app requiring the permission to do so
•an app performing almost any action on the victim's phone.

"All these issues were caused by Samsung-specific software or customizations," he noted. "All the vulnerabilities I reported can be exploited from an unprivileged local application. In other words, no specific Android privileges are required for the attacks to succeed. This allows attackers to conceal the exploit code inside a low-privileged (and apparently benign) application, distributed through Google Play or the Samsung Apps market."

He admits at being surprised at the length of time it takes for Samsung to patch the vulnerabilities, especially because he believes they are easily fixed. The company replied to him that "any patches [Samsung] develops must first be approved by the network carriers."

In the meantime, UK blogger Terence Eden has demonstrated another lock screen bypass flaw he found on Samsung Android phones, which allows anyone to completely disable the lock screen and get access to any app.

The lock screen bypass flaw he discovered earlier this month has still not been patched by Samsung, but Bkav has released a patch that not only fixes the flaw, but also takes a photo of anyone trying to misuse the flaw and emails it to the phone's owner.

UPDATE (March 22): Bkav has developed a patch for the Samsung lock screen flaw disclosed by Eden.