Feeds

Google's cookie crumbles under scripting attack

Taking the biscuit

The Essential Guide to IT Transformation

Security researchers have unpicked a flaw in Google spreadsheets that allows cookie stealing. The cross-site scripting vulnerability enables attackers to use stolen cookies to access any Google service a user has registered, including accessing a victim's Google mail account.

Google has now plugged the vulnerability, discovered by security researcher Billy Rios. In a blog posting, Rios explains a caching flaw by Google, alongside problems in how browsers handle content-type headers, created a cookie stealing risk. A Google cookie is valid across all its sub domains, a convenience factor that greatly enhances the potential for mischief.

This particular XSS vulnerability on Google's domain takes advantage of how IE determines the content type of the HTTP response being returned by the server. Other browsers have problems in handling content-type headers properly, but this vulnerability is limited to IE.

Rios created a spreadsheet which contained HTML and a string of JavaScript code for viewing a user's cookie. He then saved this spreadsheet and generated a link for the spreadsheet to be served as a text-based CSV file, which IE mistakenly interprets as HTML.

Anyone viewing this doctored spreadsheet would hand over their cookies to Rios, or potentially an attacker, as explained here. Fortunately, Google has now rendered crafted table content as text rather than HTML.

Rios has been active in identifying XSS flaws in Google's web applications. Last week, he published an advisory about a flaw in Google code that lent itself to stealing users' passwords. Prior to that, Rios uncovered vulnerabilities in Google's Picasa, Heise Security adds. ®

HP ProLiant Gen8: Integrated lifecycle automation

More from The Register

next story
USA to insist on pre-flight mobe power probe
Prove it works or it can't come aboard flights to USA
Brit celebs' homes VANISH from Google's Street View
Tony Blair's digs now a Tone-y Blur
Computing student jailed after failing to hand over crypto keys
Sledgehammer once again used to crack a nut
Doctor Who season eight scripts leak online
BBC asks fans to EXTERMINATE copies before they materialise
Snowden leaks latest: NSA, FBI g-men spied on Muslim-American chiefs
US Navy veteran? Lawmaker? Academic? You're all POTENTIAL TERRORISTS
Insecure AVG search tool shoved down users' throats, says US CERT
Sneaky 'foistware' downloads install things you never asked for
Russian MP fears US Secret Service cuffed his son for Snowden swap
Seleznev Jnr is 'prolific trafficker in stolen credit card data', it is alleged
That 'wiped' Android phone you bought is stuffed with NAKED SELFIES – possibly
Infosec bods sound alarm after copping eyefuls of nudie pics
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
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.
The Power of One eBook: Top reasons to choose HP BladeSystem
Only the Power of One delivers leading infrastructure convergence, availability and scalability with federation, and agility through data center automation.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.