Another reason for Windows users to hate the Microsoft Patch Tuesday policy,

The exploit isn’t 100% reliable but it’s still fairly significant in my eyes as it is a critical vulnerability and can be used for code execution.

Vista isn’t the most popular OS still so perhaps Microsoft don’t the threat being that wide as the protocol this exploit focuses on (SMB 2) was only introducted in Vista.

A security researcher has downplayed the significance of publicly released attack code exploiting a critical vulnerability in newer versions of Windows, saying it isn’t reliable enough to force Microsoft to issue an emergency patch. The exploit, which on Monday was folded into the open-source Metasploit penetration testing kit, is at best successful only 50 percent of the time, said Dave Aitel, CTO of security firm Immunity. Given the burden of releasing out-of-schedule patches, Microsoft is unlikely to do so in this case. “To move something like Microsoft you’ve got to have something major and this isn’t quite it,” Aitel, whose company released its own attack code two weeks ago. “It’s going to be a lot of work to take the exploit where it is to something that works enough that they will do that.”

It seems like the exploit is more reliable with Windows on VMware, but honestly how commonly do you see that? With a real native Windows installation they are only seeing a 10% success rate.

Which really isn’t that serious is it?

Apparently Immunity have made it much more reliable, but they have poured a ton of resources into it.

The vulnerability, which surfaced three weeks ago, resides in file-sharing technology called SMB2, short for server message block version 2, which was first added to Windows Vista and later made its way into newer versions of the operating system. While the Metasploit exploit is sophisticated, it is frequently thwarted by a security measure known as ASLR. Short for address space layout randomization, it picks a different memory location to load system components each time the OS is started. Without being able to predict where required code will be located, the Metasploit attack isn’t reliable enough to prompt Microsoft to take the drastic step of releasing a patch outside of the regularly scheduled update cycle. The software giant adopted the patch routine to make life easier on system administrators by allowing them to plan and test updates before installing them on huge numbers of business critical machines. The Metasploit exploit in many cases is able to get around ASLR by targeting memory locations that are predictable when Windows is running on VMware. But when the exploit targets the OS running directly on a computer, the success rate can be as low as 10 percent.

Microsoft will patch this eventually, but I doubt it’ll be soon and they definitely won’t be rushing an out-of-schedule patch out just for this vulnerability.

The question is can the bad guys fashion this into a reliable exploit and get some major ownage going on?

Source: The Register