Android browser flaw exposes user data

Potential harm is limited, however, by a few basic Android features. Here's how to protect your Android smartphone.

A vulnerability in the Android browser could permit an attacker to steal the user's local data, according to a report yesterday from security expert, Thomas Cannon.

Specifically, a malicious Website could use the flaw to access the contents of files stored on the device's SD card as well as "a limited range of other data and files stored on the phone," Cannon explained.

In essence, the problem arises because the Android browser doesn't prompt the user when downloading a file. "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 noted.

A video included with Cannon's post demonstrates the exploit in action using the Android emulator with Android 2.2, or Froyo, but Cannon has found it on an HTC Desire with Android 2.2 as well. Heise Security was able to reproduce the exploit on both a Google Nexus One and a Samsung Galaxy Tab, both running Android 2.2, according to a report on The H.

For the demo, Cannon first created a file on the SD card of the Android device. Next, he visited a malicious page and watched as it grabbed the file and automatically uploaded it to a server.

Protective Measures

The Android Security Team responded within 20 minutes of Cannon's notification about the flaw and is planning a fix that will go into a Gingerbread maintenance release after that version becomes available, he said. An initial patch has already been developed and is now being evaluated.

In the meantime, since not all gadget manufacturers provide timely Android updates, Cannon suggests a few steps users can take to protect themselves, including:

* Disabling JavaScript in the browser.

* Watching for suspicious automatic downloads, which should be flagged in the notification area. "It shouldn't happen completely silently," Cannon notes.

* Using a browser such as Opera Mobile, which prompts the user before downloading files.

* Unmounting the SD card.

The Android Advantage

Though it is clearly a vulnerability that needs to be addressed, there is good news in Cannon's discovery as well.

First, "it is not a root exploit, meaning it runs within the Android sandbox and cannot grab all files on the system," Cannon pointed out. Rather, it exposes only files on the SD card and "a limited number of others." System directories, in other words, remain protected.

Second, "you have to know the name and path of the file you want to steal," he added.

In other words, Android's Linux roots serve to protect the user from anything more than local damage, and that damage is limited to files whose names and paths are predictable, such as pictures taken with the device's camera.

Follow Katherine Noyes on Twitter: @Noyesk.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags open sourcebrowsersGooglesoftwareapplicationsPhonesconsumer electronicsCell Phonesonline securitybrowser security

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Katherine Noyes

PC World (US online)
Show Comments

Father’s Day Gift Guide

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?