Microsoft Security Bulletin MS13-048 - Important

This security update resolves one privately reported vulnerability in Windows. The vulnerability could allow information disclosure if an attacker logs on to a system and runs a specially crafted application or convinces a local, logged-in user to run a specially crafted application. An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability. Note that this vulnerability would not allow an attacker to execute code or to elevate their user rights directly, but it could be used to produce information that could be used to try to further compromise an affected system.

This security update is rated Important for all supported releases of Microsoft Windows. 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 the Windows kernel handles certain page fault system calls. 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 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.

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 

Non-Affected Software

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

• Mateusz "j00ru" Jurczyk of Google Inc for reporting the Kernel Information Disclosure Vulnerability (CVE-2013-3136)

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 (June 11, 2013): Bulletin published.
• V1.1 (June 12, 2013): Updated the Known Issues entry in the Knowledge Base Article section from "None" to "Yes".
• V1.2 (June 18, 2013): Bulletin revised to announce a detection change in the security update for 2839229 to address the known issue documented in Microsoft Knowledge Base Article 2839229. This is a detection change only. Customers who have already successfully updated their systems do not need to take any action.