Feeds

Unpatched IE bug exposes sensitive Facebook creds

'Cookiejacking' also threatens Gmail, Twitter

Internet Security Threat Report 2014

A security researcher has devised an attack that remotely steals digital credentials used to access user accounts on Facebook and other websites by exploiting a flaw in Microsoft's Internet Explorer browser.

Independent researcher Rosario Valotta demonstrated his “cookiejacking” proof of concept last week at the Hack in the Box security conference in Amsterdam. It exploits a flaw that's present in all current versions of IE to steal session cookies that Facebook and other websites issue once a user has entered a valid password and corresponding user name. The cookie acts as a digital credential that allows the user to access a specific account.

The proof of concept code specifically targets cookies issued by Facebook, Twitter and Google Mail, but Valotta said the technique can be used on virtually any website and affects all versions of Windows.

“You can steal any cookie,” he told The Register. “There is a huge customer base affected (any IE, any Win version).”

The attack exploits a vulnerability in the IE security zones feature that allows users to segregate trustworthy websites from those they don't know or don't ever want to access. By embedding a special iframe tag in a malicious website, an attacker can circumvent this cross zone interaction and cause the browser to expose cookies stored on the victim's computer.

The exploit requires the attacker to accomplish a variety of difficult tasks, including knowing where on a hard drive cookies are stored (it can be slightly different for various versions of Windows) and knowing the victim's Windows username.

Valotta's exploit incorporates techniques developed by researchers including one by Jorge Medina that manipulates file-sharing functionality built into IE to transmit the Windows username in plain text. It also borrows an advanced form of clickjacking, known as drag & drop content extraction, which was demonstrated last year by Paul Stone.

A video of Valotta's attack in action is below.

“It is complicated for the attacker but not for the victim,” Valotta said.

Microsoft spokesman Pete Voss issued a statement that read in part:

"We are aware of an issue that could enable theft of a user's cookies if they were convinced to visit a malicious website and once there, further convinced to click and drag items around on the page. Given the level of required user interaction, this issue is not one we consider high risk in the way a remote code execution would possibly be to users."

He also said attackers can steal cookies only from websites the victim is logged into. He went on to say users should avoid suspicious links.

Valotta said he first alerted members of Microsoft's security team in January. He said the company intends to patch the vulnerability in a series of updates tentatively scheduled for June and August. ®

Internet Security Threat Report 2014

More from The Register

next story
George Clooney, WikiLeaks' lawyer wife hand out burner phones to wedding guests
Day 4: 'News'-papers STILL rammed with Clooney nuptials
Shellshock: 'Larger scale attack' on its way, warn securo-bods
Not just web servers under threat - though TENS of THOUSANDS have been hit
Apple's new iPhone 6 vulnerable to last year's TouchID fingerprint hack
But unsophisticated thieves need not attempt this trick
PEAK IPV4? Global IPv6 traffic is growing, DDoS dying, says Akamai
First time the cache network has seen drop in use of 32-bit-wide IP addresses
Oracle SHELLSHOCKER - data titan lists unpatchables
Database kingpin lists 32 products that can't be patched (yet) as GNU fixes second vuln
Who.is does the Harlem Shake
Blame it on LOLing XSS terroristas
Researchers tell black hats: 'YOU'RE SOOO PREDICTABLE'
Want to register that domain? We're way ahead of you.
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
The next step in data security
With recent increased privacy concerns and computers becoming more powerful, the chance of hackers being able to crack smaller-sized RSA keys increases.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.