U radu programskog paketa Microsoft Excel uočen je sigurnosni propust koji udaljenom napadaču omogućuje pokretanje proizvoljnog programskog koda, preuzimanje potpune kontrole nad sustavom te izmjenu podataka.

Microsoft Security Bulletin MS11-096 - Important
Vulnerability in Microsoft Excel Could Allow Remote Code Execution (2640241)

Published: Tuesday, December 13, 2011

Version: 1.0
General Information
Executive Summary

This security update resolves a privately reported vulnerability in Microsoft Office. The vulnerability could allow remote code execution if a user opens a specially crafted Excel file. An attacker who successfully exploited this vulnerability 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-2011-3403. 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.

This security update is rated Important for all supported editions of Microsoft Excel 2003 and Microsoft Office 2004 for Mac. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correcting the way that Microsoft Excel manages objects in memory. For more information about the vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.

Recommendation. Customers can configure automatic updating to check online for updates from Microsoft Update by using the Microsoft Update service. Customers who have automatic updating enabled and configured to check online for updates from Microsoft Update typically will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates from Microsoft Update and install this update manually. For information about specific configuration options in automatic updating in supported editions of Windows XP and Windows Server 2003, see Microsoft Knowledge Base Article 294871. For information about automatic updating in supported editions of Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2, see Understanding Windows automatic updating.

For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update at the earliest opportunity using update management software, or by checking for updates using the Microsoft Update service.

See also the section, Detection and Deployment Tools and Guidance, later in this bulletin.

Known Issues. Microsoft Knowledge Base Article 2640241 documents the currently known issues that customers may experience when installing this security update. The article also documents recommended solutions for these issues.
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Affected and Non-Affected Software

The following software have been tested to determine which versions or editions are affected. Other versions or editions are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, visit Microsoft Support Lifecycle.

Affected Software
Microsoft Office Suite and Other Software	Component	Maximum Security Impact	Aggregate Severity Rating	Bulletins Replaced by this Update
Microsoft Office Suites and Components
Microsoft Office 2003 Service Pack 3	Microsoft Excel 2003 Service Pack 3
(KB2596954)	Remote Code Execution	Important	MS11-072
Microsoft Office for Mac
Microsoft Office 2004 for Mac
(KB2644358)	Not applicable	Remote Code Execution	Important	MS11-072

Non-Affected Software 
Office and Other Software
Microsoft Excel 2007 Service Pack 2 and Microsoft Excel 2007 Service Pack 3
Microsoft Excel 2010 and Microsoft Excel 2010 Service Pack 1 (32-bit editions)
Microsoft Excel 2010 and Microsoft Excel 2010 Service Pack 1 (64-bit editions)
Microsoft Office 2008 for Mac
Microsoft Office for Mac 2011
Open XML File Format Converter for Mac
Microsoft Excel Viewer Service Pack 2
Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats Service Pack 2
Microsoft Excel Web App 2010 and Microsoft Excel Web App 2010 Service Pack 1
Microsoft Works 9
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Frequently Asked Questions (FAQ) Related to This Security Update
Vulnerability Information
Severity Ratings and Vulnerability Identifiers
Record Memory Corruption Vulnerability - CVE-2011-3403
Update Information
Detection and Deployment Tools and Guidance
Security Update Deployment
Other Information
Acknowledgments

Microsoft thanks the following for working with us to help protect customers:

    An anonymous researcher, working with VeriSign iDefense Labs, for reporting the Record Memory Corruption Vulnerability (CVE-2011-3403)

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Microsoft Active Protections Program (MAPP)

To improve security protections for customers, Microsoft provides vulnerability information to major security software providers in advance of each monthly security update release. Security software providers can then use this vulnerability information to provide updated protections to customers via their security software or devices, such as antivirus, network-based intrusion detection systems, or host-based intrusion prevention systems. To determine whether active protections are available from security software providers, please visit the active protections Web sites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.
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Support

    Customers in the U.S. and Canada can receive technical support from Security Support or 1-866-PCSAFETY (1-866-727-2338). There is no charge for support calls that are associated with security updates. For more information about available support options, see Microsoft Help and Support.
    International customers can receive support from their local Microsoft subsidiaries. There is no charge for support that is associated with security updates. For more information about how to contact Microsoft for support issues, visit the International Support Web site.

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Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
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Revisions

    V1.0 (December 13, 2011): Bulletin published.