9.3 - MS11-045

Severity Rating: Important

Revision Note: V1.1 (August 10, 2011): Removed two erroneous workarounds in this bulletin's vulnerability section for CVE-2011-1276. This is an informational change only.

Summary: This security update resolves eight privately reported vulnerabilities in Microsoft Office. 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. 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. Installing and configuring Office File Validation (OFV) to prevent the opening of suspicious files blocks the attack vectors for exploiting the vulnerabilities described in CVE-2011-1272, CVE-2011-1273, and CVE-2011-1279. See the section, Frequently Asked Questions (FAQ) Related to This Security Update, for more information about how the Office File Validation feature can be configured to block the attack vectors. Microsoft Excel 2010 is only affected by CVE-2011-1273 described in this bulletin. The automated Microsoft Fix it solution, "Disable Edit in Protected View for Excel 2010," available in Microsoft Knowledge Base Article 2501584, blocks the attack vectors for exploiting CVE-2011-1273.