Android "Master Key" hack allows access to apps, data and even phone functions

Android "Master Key" hack allows access to apps, data and even phone functions
android master key hack

The Bluebox Security research team at Bluebox Labs have discovered a vulnerability in Android's security that allows a hackers to modify an APK code without breaking an apps cryptographic signature, which basically can turn any legitimate application into a Trojan which will be unnoticeable by the user and Play store itself.

This vulnerability, around at least since the release of Android 1.6 (codename: “Donut” ), could affect any Android phone released in the last 4 years1 – or nearly 900 million devices2– and depending on the type of application, a hacker can exploit the vulnerability for anything from data theft to creation of a mobile botnet.

While the risk to the individual and the enterprise is great (a malicious app can access individual data, or gain entry into an enterprise), this risk is compounded when you consider applications developed by the device manufacturers (e.g. HTC, Samsung, Motorola, LG) or third-parties that work in cooperation with the device manufacturer (e.g. Cisco with AnyConnect VPN) – that are granted special elevated privileges within Android – specifically System UID access.

According to Bluebox the installation of a trojan app can grant the application full access to Android and all the applications and data installed such as email, SMS, documents, retrieve accounts, service passwords and even use functions such as phone calls, record calls and turn on the camera.

How it works:

The vulnerability involves discrepancies in how Android applications are cryptographically verified & installed, allowing for APK code modification without breaking the cryptographic signature.

All Android applications contain cryptographic signatures, which Android uses to determine if the app is legitimate and to verify that the app hasn’t been tampered with or modified. This vulnerability makes it possible to change an application’s code without affecting the cryptographic signature of the application – essentially allowing a malicious author to trick Android into believing the app is unchanged even if it has been.

Details of Android security bug 8219321 were responsibly disclosed through Bluebox Security’s close relationship with Google in February 2013. It’s up to device manufacturers to produce and release firmware updates for mobile devices (and furthermore for users to install these updates). The availability of these updates will widely vary depending upon the manufacturer and model in question.

Read more about the hack and how to prevent it by hitting the source link.

Source: Bluebox