Feeds

How to expose Gmail contacts without really trying

Onslaught of Google bugs continues

Securing Web Applications Made Simple and Scalable

Google security lieutenants can't get a break. Over the past week, they've taken a public pounding, following reports of at least four previously undisclosed holes that included new cracks in Gmail and weaknesses that jeopardize the privacy of those who rely on the site to organize photos or administer their websites.

Screenshot of browser window displaying Gmail contact

Pwnd by Billy (BK) Rios

Now comes a post from the Billy (BK) Rios Blog that demonstrates yet another way to siphon contacts; the code could be easily modified to steal email and other data users may entrust to the Google.com domain.

Google bug squashers fixed the bug, but not before we witnessed it first hand. We set up our own Google account for purposes of testing the proof-of-concept code and within 10 seconds it exposed our sole Gmail contact. (A screen shot is provided to the right.) Note: for the exploit to work, the user had to be logged in to Google.

The proof-of concept code draws on a weakness in the way Google Docs handles cross-domain requests. An attacker can create a standard Flash object on a malicious server that links to a Google Docs file titled Crossdomain.xml and gain full access to the victim's Google contents, according to the post.

"The PoC just displays your contact list, but I have full access to the Google.com domain, so the sky is the limit (aka I can read all your email too)," the author wrote. "It seems that Google has taken some measures to sanitize for XSS ... but it seems that their focus on XSS may have caused them t miss a different type of cross domain exposure."

XSS is shorthand for cross site scripts, a means of injecting unauthorized code by making it appear as if it's hosted by a trusted website. At least three of the four previous Google vulnerabilities were based on XSS weaknesses, but this one is not. Instead it exploits a related bu new method for making cross domain requests.

"Google takes the security of our users' information very seriously," a Google spokeswoman said. "We worked quickly to address the recently reported vulnerability, and we have rolled out a fix."

The speed with which the flaw was fixed is testament to efficacy of Google's security team. It also speaks to one of the silver linings of web-based vulnerabilities, which frequently can be patched by applying new code on a single server. By comparison, software makes such as Microsoft and Apple must push out updates to millions of individual machines. ®

The smart choice: opportunity from uncertainty

More from The Register

next story
BMW's ConnectedDrive falls over, bosses blame upgrade snafu
Traffic flows up 20% as motorway middle lanes miraculously unclog
Putin: Crack Tor for me and I'll make you a MILLIONAIRE
Russian Interior Ministry offers big pile o' roubles for busting pro-privacy browser
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.