As Microsoft prepares to release its latest patches, researchers said they've seen exploit code for a new flaw that puts organizations using Vista and Windows 7 at great risk.
The flaw lies in the SMB (Server Message Block) 2 software in Windows, said Bojan Zdrnja, a handler for the SANS Internet Storm Center. Exploit code was released around 11 p.m. U.S. Eastern time, he said.
[ Are you up to snuff in your security regimen? Get your defenses in tip-top shape with InfoWorld's Security Boot Camp, a 20-lesson course via e-mail that begins Sept. 21. ]
Zdrnja said he tested the exploit code and it works on fully patched Vista machines running Service Pack 1 or 2 as well as Windows 7. It may also affect Windows Server 2008. When successfully attacked, the exploit will cause the targeted machine to crash.
"You get the blue screen of death," Zdrnja said.
Researchers don't know yet if the flaw is remotely exploitable, he said. Just one malicious packet is needed to crash a machine. Most PCs on internal networks keep port 445 open, which is used for file sharing.
That's dangerous, since if a hacker already has access to a compromised computer within the network, it would be possible to crash all the other machines, Zdrnja said. Administrators should disable access to the port.
Home users usually have that port open, too, Zdrnja said. But for users who join a public Wi-Fi network, Windows will ask if it is a public network and, if it is, then block port 445.
A module for the exploit has already been created for Metasploit, a hacker toolkit used to attack PCs, Zdrnja said.
Microsoft is due to release its five patches on Tuesday, all for "critical" flaws, the company's most severe threat rating. Zdrnja said it's not known if this latest flaw will be addressed.
If it isn't patched on Tuesday, Zdrnja said the flaw is so potentially harmful that he would not be surprised if Microsoft did an off-schedule patch release.
"This is really serious," Zdrnja said. "It can potentially affect a huge number of machines."
The SANS Internet Storm Center has published a short diary entry about the flaw. Microsoft officials did not have an immediate comment but said they were investigating.
Correction: This article as originally posted contained an error regarding the feature in Windows that contains a vulnerability. The story has been amended.
Get the independent advice and expertise you need to support a virtual workforce.
The increase in Linux popularity has increased the frequency and sophistication of malware attacks. Read this 2 page white paper now to learn how you can protect your Linux environment with real-time protection that is certified by all major Linux vendors.
Download now »
Ensuring acceptable application delivery will become even more difficult over the next few years. As a result, IT organizations need to ensure that the approach that they take to resolving the current application delivery challenges can scale to support the emerging challenges. This handbook elaborates on the key tasks associated with planning, optimization, management and control and provides decision criteria to help IT organizations choose appropriate solutions.
Download now »
A common misconception is that mid-range storage requirements are dramatically different than that of a larger enterprise. Mid-range storage users may require less capacity, but they have similar functionality and management requirements. This ESG paper examines mid-range storage needs and reviews a new solution that adjusts size while retaining value, performance and functionality.
Download now »
Sign up to receive InfoWorld Resource Alerts
This white paper provides guidance on how to develop a strategic approach to managing and monitoring logs, a key function required for compliance with many regulatory mandates and a critical defense against security threats.
Download now! »
Learn about the processes and technologies that support security information management (SIM) operations, as well as the business case for SIM. The series examines different options for implementing SIM and gives you evaluation criteria for selecting the best option for your organization.
Download now! »
Learn the strategies, actions, and capabilities that Best-in-Class organizations employ and technologies they choose to obtain superior performance against various security performance metrics. This report provides guidelines for identifying which security solutions to consume as a MSS and defines best practices for choosing and managing MSSPs.
Download now! »
19 Recommendations
