IE Windows vuln coughs up local files
One click bares entire C drive
If you use any version of Internet Explorer to surf Twitter or other Web 2.0 sites, Jorge Luis Alvarez Medina can probably read the entire contents of your primary hard drive.
The security consultant at Core Security said his attack works by clicking on a single link that exploits a chain of weaknesses in IE and Windows. Once an IE user visits the booby-trapped site, the webmaster has complete access to the machine's C drive, including files, authentication cookies - even empty hashes of passwords.
This isn't the first time security researchers at Core have identified security weaknesses in IE. The company issued this advisory in 2008 and this one in 2009, each identifying specific links in the chain that could potentially be abused by an attacker.
"Every time we reported this to Microsoft, they were fixing just one of the features," Medina said in a telephone interview from Bueno Aires. "Every time they [fixed] it, we managed another way to build the attack again."
Medina said he has fully briefed Microsoft on his latest attack, which he plans to demonstrate at next month's Black Hat security conference in Washington, DC. Microsoft's "rapid response team" didn't reply to an email, but a statement sent to other news outlets said the company is investigating the vulnerability and isn't aware of it being exploited in the wild.
The hole is difficult to close because the attack exploits an array of features IE users have come to rely on to make web application work seamlessly. Simply removing the features could neuter functions such as online file sharing and active scripting, underscoring the age-old tradeoff between a system's functionality and its security.
Based on Medina's characterization, it appears that fixing the weakness will require changes in a Windows network sharing technology known as SMB, or server message block, as well as the way Windows makes file caches available to a wide variety of applications.
"The things we are reporting are not bugs, they are features," Medina said. "They are needed for many applications to work, so [Microsoft] can't simply remove or truncate" them.
IE suffers from at least one other long-standing security bug that can enable attacks against people browsing websites that are otherwise safe to view. It can be exploited to introduce XSS, or cross-site scripting, exploits on webpages, allowing attackers to inject malicious content and code. Microsoft has said it's unaware of this vulnerability being exploited.
Core's previous advisories contain a number of workarounds, including setting the security level for the internet and intranet zones to high to prevent IE from running scripts or ActiveX controls. ®
It's the Microsoft w-a-a-a-a-a-y!
Create features, functions, and facilities that are inherently insecure! Yee haw!
ActiveX was the first significant step down this long and slippery slope. There's an O'Reilly book on HTML from about the time of ActiveX's debut, when Netscape was still the godzilla of browsers. In it, the author specifically warns against using ActiveX on a webpage because of the security risk. Did Microsoft act responsibly? No, of course not.
From another perspective, what MS has done over the years is to tightly integrate the OS and all applications (at least those from MS). Doing this has the effect of making those apps a part of the OS, increasing the size of the OS, and hence increasing the likelihood of there being security holes.
This is nothing new. Windows and, iirc, DOS have had undocumented trap doors in them for many years, so Excel could do its own memory allocation and thereby bypass the inefficient scheme in the OS.
The thing I wonder is this: why can a small security firm figure out these holes, yet MS, with its hordes of employees, can't? Can it possibly be that MS doesn't hire the best and the brightest, or is it that it simply doesn't bother to look at the security implications of various bells and whistles?
Don't tell me it's so!
RE:ActiveX, it's a disaster!
YouTube works just fine without it.
Millions of Linux and Mac users could tell you that.
The obvious solution
is to skip IE.