Technical Information

Brief overview of the risk:
The vulnerabilities could allow remote code execution if a user opens a specially crafted Excel file. An attacker who successfully exploited any of these vulnerabilities could gain the same user rights as the logged-on user.
Detailed Information on the risk:

A remote code execution vulnerability exists in the way that Microsoft Excel handles specially crafted Excel files. An attacker who successfully exploited this vulnerability could 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 : MS11-021