Oh no, you're thinking, yet another cookie pop-up. Well, sorry, it's the law. We measure how many people read us, and ensure you see relevant ads, by storing cookies on your device. If you're cool with that, hit “Accept all Cookies”. For more info and to customize your settings, hit “Customize Settings”.

Review and manage your consent

Here's an overview of our use of cookies, similar technologies and how to manage them. You can also change your choices at any time, by hitting the “Your Consent Options” link on the site's footer.

Manage Cookie Preferences
  • These cookies are strictly necessary so that you can navigate the site as normal and use all features. Without these cookies we cannot provide you with the service that you expect.

  • These cookies are used to make advertising messages more relevant to you. They perform functions like preventing the same ad from continuously reappearing, ensuring that ads are properly displayed for advertisers, and in some cases selecting advertisements that are based on your interests.

  • These cookies collect information in aggregate form to help us understand how our websites are being used. They allow us to count visits and traffic sources so that we can measure and improve the performance of our sites. If people say no to these cookies, we do not know how many people have visited and we cannot monitor performance.

See also our Cookie policy and Privacy policy.

This article is more than 1 year old

UK boffins steal smartmobe PINs with motion sensors

W3C API exposes sensors, so attackers only need JavaScript to follow your fingers

Updated with Apple fix The World Wide Web Consortium might want to take another look at its habit of exposing too much stuff to application interfaces: a UK researcher has demonstrated a JavaScript app can spy on smartphone sensors to guess the codes users employ to unlock the devices.

The attack, published in the International Journal of Information Security, wouldn't be possible if it weren't for a convenient API to motion sensors.

The researchers, led by Dr Maryam Mehrnezhad of Newcastle University in the UK, found that a JavaScript app can get enough information from motion sensors to crack 70 per cent of four-digit PINs at the first try.

By the third attempt, Mehrnezhad's “PINlogger.js” script is correctly guessing 94 percent of PINs.

As he explains in the Newcastle University media release, “mobile apps and websites don’t need to ask permission to access most of them, malicious programs can covertly ‘listen in’ on your sensor data and use it to discover a wide range of sensitive information about you such as phone call timing, physical activities and even your touch actions, PINs and passwords”.

If a user was tricked into loading the PIN-logger into one tab of a browser, and ran a banking app in another tab, Mehrnezhad reckons the script can also snoop on their bank logins.

The paper explains that vendors probably didn't think in-browser access to motion sensors would be so revealing because of their low sampling rates.

Mehrnezhad's team had already identified single digits from smartphone sensors, including “click, scroll, and zoom and even the numpad’s digits”. With PINlogger.js, the group extends their work to capturing 4-digit sequences.

“W3C specifications do not specify any policy and do not discuss any risks associated with this potential vulnerability,” the paper notes.

The Register has previously noted the W3C's aggressive attitude to exposing new and intrusive interfaces to Websites. Privacy researcher Lukasz Olejnik has highlighted potentially harmful Web APIs for battery charge and Bluetooth devices.

Mehrnezhad doesn't call for review or removal of the APIs, but says browser providers haven't yet come up with a solution. ®

Youtube Video

Update: Apple didn't make any noise about it, but it's blocked this issue in its latest round of security updates. It now bars access to sensor information unless the Web view is active. ®

 

Similar topics

TIP US OFF

Send us news


Other stories you might like