This security update resolves one publicly disclosed vulnerability in a Microsoft Office shared component that is currently being exploited. The vulnerability could allow security feature bypass if a user views a specially crafted webpage in a web browser capable of instantiating COM components, such as Internet Explorer. In a web-browsing attack scenario, an attacker who successfully exploited this vulnerability could bypass the Address Space Layout Randomization (ASLR) security feature, which helps protect users from a broad class of vulnerabilities. The security feature bypass by itself does not allow arbitrary code execution. However, an attacker could use this ASLR bypass vulnerability in conjunction with another vulnerability, such as a remote code execution vulnerability that could take advantage of the ASLR bypass to run arbitrary code.
This security update is rated Important for supported editions of Microsoft Office 2007 and Microsoft Office 2010 software. The security update addresses the vulnerability by helping to ensure that the Microsoft Office shared component properly implements ASLR.