Technical Information

Brief overview of the risk:
This security update resolves a privately reported vulnerability in the Windows Message Queuing Service (MSMQ). The vulnerability could allow elevation of privilege if a user received a specially crafted request to an affected MSMQ service.
Detailed Information on the risk:

An elevation of privilege vulnerability exists in the Windows Message Queuing service (MSMQ) due to a specific flaw in the parsing of an IOCTL request to the Message Queuing service. The MSMQ service improperly checks input data before passing them to the buffer. An attacker who successfully exploited this vulnerability could execute arbitrary code and take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Further information on this exploit is available at : MS09-040