Android browser flaw allows attackers to access user data

A vulnerability in the Android browser that could allow attackers to download files stored on the mobile device’s or tablet’s SD card has been discovered by security expert Thomas Cannon, and details of which have already been shared with Google – who is testing a fix as we speak.

The flaw seemingly affects all versions of Android, and could be exploited if the users surfs onto a specially crafted malicious website, where a HTML file containing JavaScript is downloaded to the device without the user being asked permission.

The JavaScript makes the payload open automatically – again without prompting the user – and has access to the files in the SD card and, according to Cannon, “a limited range of other data and files stored on the phone.”

“This is a simple exploit involving JavaScript and redirects, meaning it should also work on multiple handsets and multiple Android versions without any effort,” he says, but luckily for the users, the attackers must know the name and path of the file they want to steal, and cannot exit Android’s sandbox to steal data other than the aforementioned one.

Cannon says that the Android Security Team has responded immediately when he contacted them, and that they have already developed a fix that will be issued after they are done testing it. The also said the fix will be implemented in the maintenance release of Android’s next version (“Gingerbread”).

Cannon offered a few helpful tips on how to avoid becoming a victim in the meantime – disable JavaScript in the browser, use the Opera Mobile browser, possibly even unmount the SD card. But, according to Chester Wisniewski, the problem with Android use runs deeper. It is an open platform that can be customized by the various carriers and cell phone manufacturers to suit their needs – and that can impact the security updating process in such a way to leave lot of users vulnerable.