Technical Information

Brief overview of the risk:
This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow denial of service if an attacker created a specially crafted SMB packet and sent the packet to an affected system.
Detailed Information on the risk:

A denial of service vulnerability exists in the way that Microsoft Server Message Block (SMB) Protocol software handles specially crafted SMB requests. An attempt to exploit the vulnerability would not require authentication, allowing an attacker to exploit the vulnerability by sending a specially crafted network message to a computer running the Server service.

Further information on this exploit is available at : MS11-048