What is the purpose of this alert?

This alert is to notify you that Microsoft has released Security Advisory 975497– Vulnerabilities in SMB Could Allow Remote Code Execution - on September 08, 2009.

Summary

Microsoft is investigating new public reports of a possible vulnerability in Microsoft Server Message Block (SMB) Protocol. We are not aware of attacks that try to use the reported vulnerabilities or of customer impact at this time.

We are actively working with partners in our Microsoft Active Protections Program (MAPP) to provide information that they can use to provide broader protections to customers.

Upon completion of this investigation, Microsoft will take the appropriate action to help protect our customers. This may include providing a security update through our monthly release process or providing an out-of-cycle security update, depending on customer needs.

Microsoft is concerned that this new report of a vulnerability was not responsibly disclosed, potentially putting computer users at risk. We continue to encourage responsible disclosure of vulnerabilities. We believe the commonly accepted practice of reporting vulnerabilities directly to a vendor serves everyone's best interests. This practice helps to ensure that customers receive comprehensive, high-quality updates for security vulnerabilities without exposure to malicious attackers while the update is being developed.

Mitigating Factors
  • Firewall best practices and standard default firewall configurations can help protect networks from attacks that originate outside the enterprise perimeter. Best practices recommend that systems that are connected to the Internet have a minimal number of ports exposed. In this case, the SMB ports should be blocked from the Internet.
  • In Windows Vista, if the network profile is set to "Public", the system is not affected by this vulnerability, since unsolicited inbound network packets are blocked by default.
  • Windows 7 and Windows Server 2008 R2 are not affected by this vulnerability.
Recommendations

Review Microsoft Security Advisory 975497 for an overview of the issue, details on affected components, mitigating factors, suggested actions, frequently asked questions (FAQs), and links to additional resources.

Customers who believe they are affected can contact Customer Service and Support (CSS) in North America for help with security update issues or viruses at no charge using the PC Safety line (866) PCSAFETY. International customers can contact Customer Service and Support by using any method found at http://www.microsoft.com/protect/worldwide/default.mspx.

Additional Resources

Thank you,

Microsoft CSS Security Team