• 10/11/2017
• 41 minutes to read
• • 

Security Bulletin

Microsoft Security Bulletin MS13-054 - Critical

Vulnerability in GDI+ Could Allow Remote Code Execution (2848295)

Published: July 09, 2013 | Updated: December 16, 2013

Version: 1.3

General Information

Executive Summary

This security update resolves a privately reported vulnerability in Microsoft Windows, Microsoft Office, Microsoft Lync, and Microsoft Visual Studio. The vulnerability could allow remote code execution if a user views shared content that embeds TrueType font files.

This security update is rated Critical for all supported releases of Microsoft Windows and affected editions of Microsoft Lync 2010 and Microsoft Lync 2013. The security update is rated Important for affected releases of Microsoft Office and supported editions of Microsoft Visual Studio .NET 2003. For more information, see the subsection, Affected and Non-Affected Software, in this section.

The security update addresses the vulnerability by correcting the way Microsoft Windows and affected software handle specially crafted TrueType Font (TTF) files. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.

Recommendation.  Most customers have automatic updating enabled and 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 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 immediately 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

Affected and Non-Affected Software

The following software has 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.

Affected Software 

Microsoft Office

TrueType Font Parsing Vulnerability - CVE-2013-3129

A remote code execution vulnerability exists in the way that affected Windows components and other affected software handle specially crafted TrueType font files. The vulnerability could allow remote code execution if a user views shared content that embeds TrueType font 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 administrative rights.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2013-3129.

Mitigating Factors

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 browsing attack scenario, an attacker could host a website that contains a webpage that is used 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.
• By default, all supported versions of Microsoft Outlook, Microsoft Outlook Express, and Windows Mail open HTML email messages in the Restricted sites zone, which disables font download by default. If a user clicks a link in an email message, the user could still be vulnerable to exploitation of this vulnerability through the web-based attack scenario. The vulnerability could also be exploited if a user opens an attachment that is sent in an email message.
• The malicious file could be sent as an email attachment, but the attacker would have to convince the user to open the attachment in order to exploit the vulnerability.

Workarounds

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:

• Disable the WebClient service

  Disabling the WebClient service helps protect affected systems from attempts to exploit this vulnerability by blocking the most likely remote attack vector through the Web Distributed Authoring and Versioning (WebDAV) client service. After applying this workaround it is still possible for remote attackers who successfully exploit this vulnerability to cause the system to run programs located on the targeted user's computer or the Local Area Network (LAN), but users will be prompted for confirmation before opening arbitrary programs from the Internet.

  To disable the WebClient Service, follow these steps:

  1. Click Start, click Run, type Services.msc and then click OK.
  2. Right-click WebClient service and select Properties.
  3. Change the Startup type to Disabled. If the service is running, click Stop.
  4. Click OK and exit the management application.

  Impact of workaround. When the WebClient service is disabled, Web Distributed Authoring and Versioning (WebDAV) requests are not transmitted. In addition, any services that explicitly depend on the Web Client service will not start, and an error message will be logged in the System log. For example, WebDAV shares will be inaccessible from the client computer.

  How to undo the workaround. 

  To re-enable the WebClient Service, follow these steps:

  1. Click Start, click Run, type Services.msc and then click OK.
  2. Right-click WebClientservice and select Properties.
  3. Change the StartuptypetoAutomatic. If the service is not running, click Start.
  4. Click OK and exit the management application.

• Block TCP ports 139 and 445 at the firewall

  These ports are used to initiate a connection with the affected component. Blocking TCP ports 139 and 445 at the firewall will help protect systems that are behind that firewall from attempts to exploit this vulnerability. Microsoft recommends that you block all unsolicited inbound communication from the Internet to help prevent attacks that may use other ports. For more information about ports, see the TechNet article, TCP and UDP Port Assignments.

  Impact of workaround. Several Windows services use the affected ports. Blocking connectivity to the ports may cause various applications or services to not function. Some of the applications or services that could be impacted are listed below:

  • Applications that use SMB (CIFS)
  • Applications that use mailslots or named pipes (RPC over SMB)
  • Server (File and Print Sharing)
  • Group Policy
  • Net Logon
  • Distributed File System (DFS)
  • Terminal Server Licensing
  • Print Spooler
  • Computer Browser
  • Remote Procedure Call Locator
  • Fax Service
  • Indexing Service
  • Performance Logs and Alerts
  • Systems Management Server
  • License Logging Service

  How to undo the workaround. Unblock TCP ports 139 and 445 at the firewall. For more information about ports, see TCP and UDP Port Assignments.

• Disable the Preview Pane and Details Pane in Windows Explorer

  Disabling the Preview and Details panes in Windows Explorer prevents TrueType fonts from being viewed in Windows Explorer. While this prevents malicious files from being viewed in Windows Explorer, it does not prevent a local, authenticated user from running a specially crafted program to exploit this vulnerability.

  To disable these panes in Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2, perform the following steps:

  1. Open Windows Explorer, click Organize, and then click Layout.
  2. Clear both the Details pane and Preview pane menu options.
  3. Open Windows Explorer, click Organize, and then click Folder and search options.
  4. Click on the View tab
  5. Check the box for Always show icons,never thumbnails under Advanced settings.
  6. Close all open instances of Windows Explorer for the change to take effect.

  How to undo the workaround. To re-enable the Windows Explorer Preview and Details panes in Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2:

  1. Open Windows Explorer, click Organize, and then click Layout.
  2. Select both the Details pane and Preview pane menu options.
  3. Open Windows Explorer, click Organize, and then click Folder and search options.
  4. Click on the View tab
  5. Clear the box for Alwaysshowicons,neverthumbnails under Advanced settings.
  6. Close all open instances of Windows Explorer for the change to take effect.

FAQ

What is the scope of the vulnerability?
This is a remote code execution vulnerability.

What causes the vulnerability?
The vulnerability is caused when Windows, Office, Visual Studio, or Lync fails to properly handle specially crafted TrueType Fonts (TTF) files.

What is TrueType?
TrueType is a digital font technology used in Microsoft operating systems.

What is GDI+?
GDI+ is a graphics device interface that provides two-dimensional vector graphics, imaging, and typography to applications and programmers.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited the vulnerability through Windows GDI+ and Windows components could run arbitrary code in kernel mode and take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full administrative rights.

An attacker who successfully exploited the vulnerability through Microsoft Office, Microsoft Visual Studio, or Microsoft Lync could gain the same user rights as the current user. If a 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?
There are multiple means that could allow an attacker to exploit this vulnerability.

In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit this vulnerability and then convince a user to view the website. An attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically by getting them to click a link in an email message or in an Instant Messenger message that takes users to the attacker's website, or by opening an attachment sent through email.

In a file sharing attack scenario, an attacker could provide a specially crafted document file that is designed to exploit this vulnerability, and then convince a user to open the document file.

In a local attack scenario, an attacker could also exploit this vulnerability by running a specially crafted application to take complete control over the affected system. However, the attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability in this scenario.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk.

What does the update do?
The update addresses the vulnerability by correcting the way Windows handles specially crafted TrueType Font (TTF) 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.

Update Information

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 information about these and other tools that are available, see Security Tools for IT Pros. 

Security Update Deployment

Affected Software

For information about the specific security update for your affected software, click the appropriate link:

Windows XP (all editions)

Reference Table

The following table contains the security update information for this software.

Note The update for supported versions of Windows XP Professional x64 Edition also applies to supported versions of Windows Server 2003 x64 Edition.

Windows Server 2003 (all editions)

Reference Table

The following table contains the security update information for this software.

Microsoft Office 2003 (all editions)

Reference Table

The following table contains the security update information for this software.

Microsoft Lync 2010, Microsoft Lync 2010 Attendee, Microsoft Lync 2013, and Microsoft Lync Basic 2013

Reference Table

The following table contains the security update information for this software.

Other Information

Acknowledgments

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

• Ling Chuan Lee and Lee Yee Chan of F13 Laboratory for reporting the TrueType Font Parsing Vulnerability (CVE-2013-3129)

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.

Support

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

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 (July 9, 2013): Bulletin published.
• V.1.1 (August 1, 2013): Bulletin revised to announce a detection change in the 2687276 update for Microsoft Office 2010. There were no changes to the security update files. Customers who have already successfully updated their systems do not need to take any action. In addition, bulletin revised to add update FAQs to help clarify the configurations to which the updates for Microsoft Office may apply.
• V1.2 (August 13, 2013): Bulletin revised to announce a detection change for the 2687276 update for Microsoft Office 2010. This detection change only affects non-English deployments. There were no changes to the security update files. Customers who have already successfully updated their systems do not need to take any action.
• V1.3 (December 16, 2013): Revised bulletin to announce a detection change to correct an offering issue for Windows RT (2835361) and for Windows RT (2835364). This is a detection change only. There were no changes to the update files. Customers who have successfully installed the update do not need to take any action.

Built at 2014-04-18T13:49:36Z-07:00