This security update resolves a privately reported vulnerability in Microsoft Visual Basic for Applications. The vulnerability could allow remote code execution if a host application opens and passes a specially crafted file to the Visual Basic for Applications runtime. If a user is logged on with administrative user rights, 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. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.