This security update resolves two publicly disclosed and six privately reported vulnerabilities in Microsoft Windows. The most severe 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.
The security update addresses these vulnerabilities by correcting the way Windows handles specially crafted TrueType Font (TTF) files and by correcting the way that Windows handles 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. 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.
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.
Why does this update address several reported security vulnerabilities?
This update contains support for several vulnerabilities because the modifications that are required to address these issues are located in related files.
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.
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 July bulletin summary. For more information, see Microsoft Exploitability Index.
An elevation of privilege vulnerability exists when the Windows kernel-mode driver improperly handles objects in memory. An attacker who successfully exploited this vulnerability could execute arbitrary code with elevated privileges.
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:
What is the Windows kernel-mode driver (win32k.sys)?Win32k.sys is a kernel-mode device driver and is the kernel part of the Windows subsystem. It contains the window manager, which controls window displays; manages screen output; collects input from the keyboard, mouse, and other devices; and passes user messages to applications. It also contains the Graphics Device Interface (GDI), which is a library of functions for graphics output devices. Finally, it serves as a wrapper for DirectX support that is implemented in another driver (dxgkrnl.sys).
How could an attacker exploit the vulnerability?
To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to increase privileges.
What systems are primarily at risk from the vulnerability?
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.
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.
An elevation of privilege vulnerability exists in the way that the Windows kernel-mode driver improperly handles objects in memory. An attacker who successfully exploited this vulnerability could execute arbitrary code with elevated privileges.
What might an attacker use the vulnerability to do?
In Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2, an attacker who successfully exploited this vulnerability could run processes in an elevated context. In Windows 8 and Windows Server 2012, an attacker who successfully exploited this vulnerability could cause the target system to stop responding.
How could an attacker exploit the vulnerability?
In an attack scenario, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to increase privileges.
A remote code execution vulnerability exists in the way that affected components handle specially crafted TrueType font files. The vulnerability could allow remote code execution if a user opens a specially crafted TrueType font file. 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.
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