Technical Information

Brief overview of the risk:
The vulnerability could allow elevation of privilege if an attacker logs on to an affected system and runs a specially crafted application designed to exploit the vulnerability. An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability. The vulnerability could not be exploited remotely or by anonymous users.
Detailed Information on the risk:

An elevation of privilege vulnerability exists in the Windows kernel due to the way the kernel accesses an object that has not been correctly initialized. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. 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 : MS11-098