Feeds

Skype for iPhone makes stealing address books a snap

Just add JavaScript

Securing Web Applications Made Simple and Scalable

If you use Skype on an iPhone or iPod touch, Phil Purviance can steal your device's address book simply by sending you a chat message.

In a video posted over the weekend, the security researcher makes the attack look like child's play. Type some JavaScript commands into the user name of a Skype account, use it to send a chat message to someone using the latest version of Skype on an iPhone or iPod touch, and load a small program onto a webserver. Within minutes, you'll have a fully-searchable copy of the victim's address book.

“I'm going to send a user on an iPhone a message, and when he sees the message, the exploit will run,” the narrator says. “When the exploit code is run, the victim's iPhone will automatically make a new connection to my server to grab a larger payload instructing the victim's iPhone to upload its entire address book file to the server.”

The attack exploits two oversights that just go to show that even elaborately erected walled gardens such as Apple's can contain threats that menace its blissful inhabitants. The first is a failure by Skype to sanitize potentially dangerous JavaScript commands from the text that gets sent in chat messages. Skype for Macs recently succumbed to a similar XSS, or cross-site scripting, vulnerability that allowed attackers to commandeer a victim's computer simply by viewing a malicious message.

The other lapse making Purviance's attack possible was the decision by iOS developers to make the file storing address-book contents accessible to every app installed, including Skype. That means all that's required to steal a full list of contacts is to find and exploit a vulnerability in a single program installed on a victim's device.

In a Web 2.0 kind of world, contacts for many people aren't exactly closely guarded secrets. For many others – say, attorneys and people who work with survivors of domestic abuse – the names, addresses and phone numbers of contacts are sensitive information.

It's already been 48 hours since this vulnerability was first documented, and the vulnerable app is still available in the iTunes Store. It will be interesting to see how long it takes Apple and Skype to close the gaping hole. ®

Mobile application security vulnerability report

More from The Register

next story
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
NEW, SINISTER web tracking tech fingerprints your computer by making it draw
Have you been on YouPorn lately, perhaps? White House website?
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Black Hat anti-Tor talk smashed by lawyers' wrecking ball
Unmasking hidden users is too hot for Carnegie-Mellon
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
NUDE SNAPS AGENCY: NSA bods love 'showing off your saucy selfies'
Swapping other people's sexts is a fringe benefit, says Snowden
Own a Cisco modem or wireless gateway? It might be owned by someone else, too
Remote code exec in HTTP server hands kit to bad guys
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.