Microsoft Security Bulletin MS13-043 - Important
Vulnerability in Microsoft Word Could Allow Remote Code Execution (2830399)
Published: May 14, 2013
This security update resolves one privately reported vulnerability in Microsoft Office. The vulnerability could allow remote code execution if a user opens a specially crafted file or previews a specially crafted email message in an affected version of Microsoft Office software. An attacker who successfully exploited this vulnerability could gain the same user rights as the current 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.
This security update is rated Important for supported editions of Microsoft Word 2003 and Microsoft Word Viewer. 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 Word parses specially crafted Office files. 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, see Microsoft Knowledge Base Article 294871.
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.
Knowledge Base Article
|Knowledge Base Article||2830399|
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, see Microsoft Support Lifecycle.
|Microsoft Office Suite and Other Software||Component||Maximum Security Impact||Aggregate Severity Rating||Updates Replaced|
|Microsoft Office Suites and Components|
|Microsoft Office 2003 Service Pack 3||
Microsoft Word 2003 Service Pack 3
|Remote Code Execution||Important||2760497 in MS12-079|
|Other Microsoft Office Software|
Microsoft Word Viewer
|Not applicable||Remote Code Execution||Important||2760498 in MS12-079|
|Office and Other Software|
|Microsoft Word 2007 Service Pack 3|
|Microsoft Word 2010 Service Pack 1|
|Microsoft Word 2013|
|Microsoft Word 2013 RT|
|Microsoft Office Compatibility Pack Service Pack 3|
|Microsoft Word Web App 2010 Service Pack 1|
|Microsoft Word Web App 2013|
|Microsoft Office for Mac 2011|
How is Microsoft Outlook affected by the vulnerability?
Microsoft Outlook is not directly affected because the vulnerability exists in Microsoft Word. However, if Word is the selected email reader, then an attacker could leverage Outlook for the email attack vector to exploit the vulnerability by sending a specially crafted RTF email message to the target user. Note that by default, Microsoft Word is not the email reader in Outlook 2003.
How areMicrosoft Office standalone programs affected by the vulnerability?
A Microsoft Office standalone program is affected with the same severity rating as the corresponding component in a Microsoft Office Suite. For example, a standalone installation of Microsoft Word is affected with the same severity rating as an installation of Microsoft Word that was delivered with a Microsoft Office Suite.
The Microsoft Office component discussed in this article is part of the Microsoft Office Suite that I have installed on my system; however, I did not choose to install this specific component. Will I be offered this update?
Yes, if the component discussed in this bulletin was delivered with the version of the Microsoft Office Suite installed on your system, the system will be offered updates for it whether the component is installed or not. The detection logic used to scan for affected systems is designed to check for updates for all components that were delivered with the particular Microsoft Office Suite and to offer the updates to a system. Users who choose not to apply an update for a component that is not installed, but is delivered with their version of the Microsoft Office Suite, will not increase the security risk of that system. On the other hand, users who do choose to install the update will not have a negative impact on the security or performance of a system.
Does the offer to update a non-vulnerable version of Microsoft Office constitute an issue in the Microsoft update mechanism?
No. The update mechanism is functioning correctly in that it detects a product version for the applicable software on the system that is within the range of product versions that the update applies to and thus, offers the update.
I am using an older release of the software discussed in this security bulletin. What should I do?
The affected software listed in this bulletin have been tested to determine which releases are affected. Other releases are past their support life cycle. For more information about the product lifecycle, see the Microsoft Support Lifecycle website.
It should be a priority for customers who have older releases of the software to migrate to supported releases to prevent potential exposure to vulnerabilities. To determine the support lifecycle for your software release, see Select a Product for Lifecycle Information. For more information about service packs for these software releases, see Service Pack Lifecycle Support Policy.
Customers who require custom support for older software must contact their Microsoft account team representative, their Technical Account Manager, or the appropriate Microsoft partner representative for custom support options. Customers without an Alliance, Premier, or Authorized Contract can contact their local Microsoft sales office. For contact information, see the Microsoft Worldwide Information website, select the country in the Contact Information list, and then click Go to see a list of telephone numbers. When you call, ask to speak with the local Premier Support sales manager. For more information, see the Microsoft Support Lifecycle Policy FAQ.
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 May bulletin summary. For more information, see Microsoft Exploitability Index.
|Affected Software||Word Shape Corruption Vulnerability - CVE-2013-1335||Aggregate Severity Rating|
|Microsoft Word 2003 Service Pack 3||Important
Remote Code Execution
|Microsoft Word Viewer||Important
Remote Code Execution
Word Shape Corruption Vulnerability - CVE-2013-1335
A remote code execution vulnerability exists in the way that Microsoft Word parses content in Word files. 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.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2013-1335.
Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors may be helpful in your situation:
- In a web-based attack scenario, an attacker could host a website that contains a specially crafted Office file that is used to attempt to exploit this vulnerability. In addition, compromised websites and websites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit this vulnerability. In all cases, however, an attacker would have no way to force users to visit these websites. 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 that takes users to the attacker’s website, and convince them to open the specially crafted Office file.
- An attacker who successfully exploited this vulnerability could gain the same user rights as the current 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.
Workaround refers to a setting or configuration change that does not correct the underlying vulnerability but would help block known attack vectors before you apply the update. Microsoft has tested the following workarounds and states in the discussion whether a workaround reduces functionality:
- Do not open Office files that you receive from untrusted sources or that you receive unexpectedly from trusted sources
Do not open Office files that you receive from untrusted sources or that you receive unexpectedly from trusted sources. This vulnerability could be exploited when a user opens a specially crafted file.
What is the scope of the vulnerability?
This is a remote code execution vulnerability.
What causes the vulnerability?
The vulnerability exists in Microsoft Word when shape data is incorrectly handled while parsing a specially crafted file.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take complete control of the 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.
How could an attacker exploit the vulnerability?
This vulnerability requires that a user open a specially crafted file or preview a specially crafted email message with an affected version of Microsoft Office software.
In an email attack scenario, an attacker could exploit the vulnerability by sending specially crafted RTF-formatted data in the contents of an email message. The vulnerability could be exploited when the specially crafted RTF email message is previewed or opened in Outlook while using Microsoft Word as the email viewer. Note that by default, Microsoft Word is not the email reader in Outlook 2003. An attacker could also exploit the vulnerability by sending a specially crafted Office file to the user, and then by convincing the user to open the file with an affected version of Microsoft Word or Microsoft Word Viewer.
In a web-based attack scenario, an attacker would have to host a website that contains an Office file that is used to attempt to exploit this 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 them to visit the website, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes them to the attacker's site, and then convince them to open the specially crafted Office file.
What systems are primarily at risk from the vulnerability?
Systems where Microsoft Word 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.
What does the update do?
This update addresses the vulnerability by correcting the way that Microsoft Word parses specially crafted Office files.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through coordinated vulnerability disclosure.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.
Detection and Deployment Tools and Guidance
Several resources are available to help administrators deploy security updates.
- Microsoft Baseline Security Analyzer (MBSA) lets administrators scan local and remote systems for missing security updates and common security misconfigurations.
- Windows Server Update Services (WSUS), Systems Management Server (SMS), and System Center Configuration Manager (SCCM) help administrators distribute security updates.
- The Update Compatibility Evaluator components included with Application Compatibility Toolkit aid in streamlining the testing and validation of Windows updates against installed applications.
For more information about these tools and guidance in deploying security updates across networks, see Security Tools for IT Pros.
Security Update Deployment
For information about the specific security update for your affected software, click the appropriate link:
Microsoft Office 2003 (all editions)
The following table contains the security update information for this software.
|Security update file name||For Microsoft Word 2003:
|For Microsoft Word Viewer:
|Installation switches||See Microsoft Knowledge Base Article 912203|
|Restart requirement||In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.
To help reduce the chance that a restart will be required, stop all affected services and close all applications that may use the affected files prior to installing the security update. For more information about the reasons why you may be prompted to restart, see Microsoft Knowledge Base Article 887012.
|Removal information||Use Add or Remove Programs item in Control Panel.
Note When you remove this update, you may be prompted to insert the Microsoft Office 2003 CD in the CD drive. Additionally, you may not have the option to uninstall the update from the Add or Remove Programs item in Control Panel. There are several possible causes for this issue. For more information about the removal, see Microsoft Knowledge Base Article 903771.
|File information||See Microsoft Knowledge Base Article 2810046 and Microsoft Knowledge Base Article 2817361|
|Registry key verification||Not applicable|
Microsoft thanks the following for working with us to help protect customers:
- Will Dormann of the CERT/CC for reporting the Word Shape Corruption Vulnerability (CVE-2013-1335)
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 go to the active protections websites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.
How to obtain help and support for this security update
- Help installing updates: Support for Microsoft Update
- Security solutions for IT professionals: TechNet Security Troubleshooting and Support
- Help protect your computer that is running Windows from viruses and malware: Virus Solution and Security Center
- Local support according to your country: International Support
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.
- V1.0 (May 14, 2013): Bulletin published.
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