Microsoft Security Bulletin MS15-013 - Important

Vulnerability in Microsoft Office Could Allow Security Feature Bypass (3033857)

Published: February 10, 2015

Version: 1.0

Executive Summary

This security update resolves one publicly disclosed vulnerability in Microsoft Office. The vulnerability could allow security feature bypass if a user opens a specially crafted Microsoft Office file. The security feature bypass by itself does not allow arbitrary code execution. However, an attacker could use this security feature bypass vulnerability in conjunction with another vulnerability, such as a remote code execution vulnerability, to run arbitrary code.

This security update is rated Important for all supported editions of Microsoft Office 2007, Microsoft Office 2010, and Microsoft Office 2013. For more information, see the Affected Software section.

The security update addresses the vulnerability by correcting how Microsoft Office parses specially crafted files. For more information about the vulnerability, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3033857.

Affected Software

The following software versions or editions are affected. Versions or editions that are not listed are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, see Microsoft Support Lifecycle

Microsoft Office Suite and Other Software Maximum Security Impact Aggregate Severity Rating Updates Replaced
Microsoft Office Suites and Components
Microsoft Office 2007
Microsoft Office 2007 Service Pack 3 (2920795) Security Feature Bypass Important None
Microsoft Office 2010
Microsoft Office 2010 Service Pack 2 (32-bit editions) (2920748) Security Feature Bypass Important None
Microsoft Office 2010 Service Pack 2 (64-bit editions) (2920748) Security Feature Bypass Important None
Microsoft Office 2013
Microsoft Office 2013 (32-bit editions) (2910941) Security Feature Bypass Important None
Microsoft Office 2013 (64-bit editions) (2910941) Security Feature Bypass Important None
Microsoft Office 2013 Service Pack 1 (32-bit editions) (2910941) Security Feature Bypass Important None
Microsoft Office 2013 Service Pack 1 (64-bit editions) (2910941) Security Feature Bypass Important None

Severity Ratings and Vulnerability Identifiers

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the February bulletin summary.  

Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software Microsoft Office Component Use After Free Vulnerability - CVE-2014-6362 Aggregate Severity Rating
Microsoft Office 2007
Microsoft Office 2007 Service Pack 3 (2920795) Important Security Feature Bypass Important
Microsoft Office 2010
Microsoft Office 2010 Service Pack 2 (32-bit editions) (2920748) Important Security Feature Bypass Important
Microsoft Office 2010 Service Pack 2 (64-bit editions) (2920748) Important Security Feature Bypass Important
Microsoft Office 2013
Microsoft Office 2013 (32-bit editions) (2910941) Important Security Feature Bypass Important
Microsoft Office 2013 (64-bit editions) (2910941) Important Security Feature Bypass Important
Microsoft Office 2013 Service Pack 1 (32-bit editions) (2910941) Important Security Feature Bypass Important
Microsoft Office 2013 Service Pack 1 (64-bit editions) (2910941) Important Security Feature Bypass Important

Vulnerability Information

Microsoft Office Component Use After Free Vulnerability - CVE-2014-6362

A security feature bypass vulnerability exists in Microsoft Office when it fails to use the Address Space Layout Randomization (ASLR) security feature, allowing an attacker to more reliably predict the memory offsets of specific instructions in a given call stack. The security feature bypass by itself does not allow arbitrary code execution. However, an attacker could use the ASLR bypass vulnerability in conjunction with another vulnerability, such as a remote code execution vulnerability, to run arbitrary code.

Exploitation of this vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Office software. In an email attack scenario an attacker could exploit the vulnerability by sending the specially crafted file to the user and by convincing the user to open the file. Note that Word Viewer and the Preview Pane are not attack vectors for this vulnerability. In a web-based attack scenario an attacker could host a website that contains a file that is used to attempt to exploit the vulnerability. In addition, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could exploit this vulnerability. An attacker would have no way to force users to visit a specially crafted website. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message, and then convince them to open the specially crafted file.

The security update addresses the vulnerability by correcting how Microsoft Office parses files. Systems where affected Microsoft Office software is used, including workstations and terminal servers, are primarily at risk. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage allowing this.

The Enhanced Mitigation Experience Toolkit (EMET) helps to mitigate this vulnerability on systems where EMET is installed and configured to work with Microsoft Office software. EMET enables users to manage security mitigation technologies that help make it more difficult for attackers to exploit vulnerabilities in a given piece of software. For more information about EMET, see The Enhanced Mitigation Experience Toolkit.

This vulnerability has been publicly disclosed. It has been assigned Common Vulnerability and Exposure number CVE-2014-6362. When this security bulletin was originally issued Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.

Mitigating Factors

Microsoft has not identified any mitigating factors for this vulnerability.

Workarounds

The following workarounds may be helpful in your situation:

  • Use the Mandatory ASLR mitigation in EMET
    Use the Enhanced Mitigation Experience Toolkit (EMET) and enable the Mandatory ASLR mitigation for at-risk applications. See Enhanced Mitigation Experience Toolkit 5.1(v=Security.10)) for more information and download links.

    Impact of workaround. EMET will force modules to load with ASLR even if they were not compiled with that setting.

    How to undo the workaround.

    Disable the Mandatory ASLR mitigation for at-risk applications or uninstall EMET.

Security Update Deployment

For Security Update Deployment information, see the Microsoft Knowledge Base article referenced in the Executive Summary.

Acknowledgments

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgments for more information. 

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.

Revisions

  • V1.0 (February 10, 2015): Bulletin published.

Page generated 2015-02-05 15:50Z-08:00.