Microsoft Security Bulletin MS14-026 - Important

• 10/11/2017
• 37 minutes to read
• • 
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Vulnerability in .NET Framework Could Allow Elevation of Privilege (2958732)

Published: May 13, 2014

Version: 1.0

General Information

Executive Summary

This security update resolves a privately reported vulnerability in Microsoft .NET Framework. The vulnerability could allow elevation of privilege if an authenticated attacker sends specially crafted data to an affected workstation or server that uses .NET Remoting. .NET Remoting is not widely used by applications; only custom applications that have been specifically designed to use .NET Remoting would expose a system to the vulnerability.

This security update is rated Important for Microsoft .NET Framework 1.1 Service Pack 1, Microsoft .NET Framework 2.0 Service Pack 2, Microsoft .NET Framework 3.5, Microsoft .NET Framework 3.5.1, Microsoft .NET Framework 4, Microsoft .NET Framework 4.5, and Microsoft .NET Framework 4.5.1 on affected releases of Microsoft Windows.

The security update addresses the vulnerability by helping to ensure that .NET Framework properly enforces security controls for application memory. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability later in this bulletin.

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

• Knowledge Base Article: 2958732
• File Information: Yes
• SHA1/SHA2 hashes: Yes
• Known issues: None

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

^[2]Windows RT and Windows RT 8.1 security updates are provided via Windows Update.

Non-Affected Software

TypeFilterLevel Vulnerability – CVE-2014-1806

An elevation of privilege vulnerability exists in the way that .NET Framework handles TypeFilterLevel checks for some malformed objects.

To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2014-1806.

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:

• .NET Remoting is not widely used by applications; only custom applications that have been specifically designed to use .NET Remoting would expose a system to the vulnerability.
• .NET Remoting endpoints are not accessible to anonymous clients by default.

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:

• Enable security when registering a channel

  Enabling security when registering a channel will allow only authenticated clients to interact with the vulnerable server. For more information see Authentication with the TCP Channel.

FAQ

What is the scope of the vulnerability?
This is an elevation of privilege vulnerability.

What causes the vulnerability?
The vulnerability is caused when the .NET Framework improperly enforces types of access controls on objects in memory.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability 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.

How could an attacker exploit the vulnerability?
An authenticated attacker could send specially crafted data to an affected workstation or server that uses .NET Remoting, allowing the attacker to execute arbitrary code on the targeted system.

What systems are primarily at risk from the vulnerability?
Systems running affected versions of .NET Framework that use .NET Remoting are primarily at risk from this vulnerability.

What is Microsoft .NET Remoting?
Microsoft .NET Remoting is a technology that simplifies how applications communicate and share objects with other applications.

What does the update do?
The update addresses the vulnerability by ensuring that .NET Framework properly enforces security controls for application memory.

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 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

Windows Server 2003 (all editions)

Reference Table

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

Windows Vista (all editions)

Reference Table

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

Windows Server 2008 (all editions)

Reference Table

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

Windows 7 (all editions)

Reference Table

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

Windows Server 2008 R2 (all editions)

Reference Table

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

Windows 8 and Windows 8.1 (all editions)

Reference Table

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

Windows Server 2012 and Windows Server 2012 R2 (all editions)

Reference Table

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