Feeds

IE 0day accidentally leaked to Chinese hackers

Oops

The Power of One eBook: Top reasons to choose HP BladeSystem

Details concerning a potentially serious security vulnerability in fully patched versions of Microsoft's Internet Explorer have been leaked to people in China, a researcher warned over the weekend.

Michal Zalewski, a security researcher at Google, blogged that data concerning at least one “clearly exploitable crash” in the Microsoft browser was inadvertently disclosed to people who were using a Chinese IP address. Details about the bug, which resides in the mshtml.dll component, were stored on a server that had accidentally been indexed by Google, Zalewski wrote elsewhere. On December 30, detailed search queries showed that the sensitive information, in addition to files for an unpublished security tool, had been retrieved by the unknown party.

“This pattern is very strongly indicative of an independent discovery of the same fault condition in MSIE by unrelated means,” Zalewski wrote. “Other explanations for this pair of consecutive searches seem extremely unlikely.”

The bug leads to arbitrary crashes in the EIP, or extended instruction pointer, of machines running the Microsoft browser. Zalewski said the flaw “is pretty much fully attacker-controlled.” It was uncovered using cross_fuzz, a security tool the researcher developed in his spare time more than two years ago to identify potential security vulnerabilities in IE, Firefox, and other browsers. Since its release, the tool has helped to identify nearly 100 various browser bugs.

A statement attributed to Jerry Bryant, group manager in Microsoft's Response Communications, said company researchers are working to reproduce the crash to see if the underlying vulnerability can be exploited by malicious hackers.

“At this point, we're not aware of any exploits or attacks for the reported issue and are continuing to investigate and monitor the threat environment for any changes,” Bryant said.

Zalewski provided this account of his communications with Microsoft, which started in May 2008. In it, he claims that on December 21, Microsoft researcher David Ross “confirms being able to reproduce crashes locally right away.”

Zalewski said that Microsoft researchers asked him to delay the release of cross_fuzz until they had more time to investigate the crashes. He published his warning on New Year's Day, after he learned that the crash logs and related files had been downloaded.

“These search queries are looking for information on two MSHTML.DLL functions – BreakAASpecial and BreakCircularMemoryReferences – that are unique to the stack signature of this vulnerability, and had *absolutely* no other mentions on the internet at that time,” he said. ®

Update

Zalewski has updated his post to make clear that he believes the individuals who accessed cross_fuzz data already knew of the IE zero day.

"The pattern is very strongly indicative of an independent discovery of the same vulnerability in MSIE with unrelated tools, eventually leading the discoverer to my site," he wrote. "Other explanations for this pair of consecutive searches seem extremely unlikely."

The Power of One eBook: Top reasons to choose HP BladeSystem

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
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
BMW's ConnectedDrive falls over, bosses blame upgrade snafu
Traffic flows up 20% as motorway middle lanes miraculously unclog
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
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.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
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.
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.