Not sure why Microsoft took time to acknowledge this?
"Microsoft has issued a security advisory to acknowledge a crippling
denial-of-service flaw affecting its newest operating systems — Windows
7 and Windows Server 2008 R2.
In the absence of a patch, Microsoft recommends that affected users
block TCP ports 139 and 445 at the firewall. Windows users should also
block all SMB communications to and from the Internet to help prevent