Vulnerability in LRPC Could Allow Security Feature Bypass (2978668)
Published: August 12, 2014
Version: 1.0
General Information
Executive Summary
This security update resolves a privately reported vulnerability in Microsoft Windows. The vulnerability could allow security feature bypass if an attacker uses the vulnerability in conjunction with another vulnerability, such as a remote code execution vulnerability, that takes advantage of the ASLR bypass to run arbitrary code.
This security update is rated Important for all supported editions of Windows 7, Windows Server 2008 R2, Windows 8, Windows 8.1, Windows Server 2012, Windows Server 2012 R2, Windows RT, and Windows RT 8.1. For more information, see the Affected and Non-Affected Software section.
The security update addresses the vulnerability by correcting how RPC handles the freeing of malformed messages. 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. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871. For customers who do not have automatic updating enabled, the steps in Turn automatic updating on or off can be used to enable automatic updating.
For administrators and enterprise installations, or end users who want to install this security update manually (including customers who have not enabled automatic updating), 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. The updates are also available via the download links in the Affected Software table later in this bulletin.
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.
Windows Server 2003 with SP2 for Itanium-based Systems
Windows Vista Service Pack 2
Windows Vista x64 Edition Service Pack 2
Windows Server 2008 for 32-bit Systems Service Pack 2
Windows Server 2008 for x64-based Systems Service Pack 2
Windows Server 2008 for Itanium-based Systems Service Pack 2
Server Core installation option
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
Update FAQ
I am running Windows 8.1, Windows Server 2012 R2, or Windows RT 8.1. Why am I not being offered this update?
To be offered any security updates on Windows 8.1, Windows Server 2012 R2, or Windows RT 8.1, the 2919355 update must be installed on the system. For more information, see Microsoft Knowledge Base Article 2919355.
For Windows 8.1, Windows Server 2012 R2, and Windows RT 8.1 are there any prerequisites for this update?
Yes. Customers running Windows 8.1, Windows Server 2012 R2, or Windows RT 8.1 must first install the 2919355 update released in April, 2014 before this update can be installed. For more information about the prerequisite update, see Microsoft Knowledge Base Article 2919355.
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 has 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 August bulletin summary. For more information, see Microsoft Exploitability Index.
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software
LRPC ASLR Bypass Vulnerability - CVE-2014-0316
Aggregate Severity Rating
Windows 7
Windows 7 for 32-bit Systems Service Pack 1 (2978668)
Important Security Feature Bypass
Important
Windows 7 for x64-based Systems Service Pack 1 (2978668)
Important Security Feature Bypass
Important
Windows Server 2008 R2
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (2978668)
Important Security Feature Bypass
Important
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) (2978668)
Important Security Feature Bypass
Important
Windows Server 2008 R2 for Itanium-based Systems Service Pack 1 (2978668)
Important Security Feature Bypass
Important
Windows 8 and Windows 8.1
Windows 8 for 32-bit Systems (2978668)
Important Security Feature Bypass
Important
Windows 8 for x64-based Systems (2978668)
Important Security Feature Bypass
Important
Windows 8.1 for 32-bit Systems (2978668)
Important Security Feature Bypass
Important
Windows 8.1 for x64-based Systems (2978668)
Important Security Feature Bypass
Important
Windows Server 2012 and Windows Server 2012 R2
Windows Server 2012 (2978668)
Important Security Feature Bypass
Important
Windows Server 2012 (Server Core installation) (2978668)
Important Security Feature Bypass
Important
Windows Server 2012 R2 (2978668)
Important Security Feature Bypass
Important
Windows Server 2012 R2 (Server Core installation) (2978668)
Important Security Feature Bypass
Important
Windows RT and Windows RT 8.1
Windows RT[1] (2978668)
Important Security Feature Bypass
Important
Windows RT 8.1[1] (2978668)
Important Security Feature Bypass
Important
LRPC ASLR Bypass Vulnerability - CVE-2014-0316
A security feature bypass vulnerability exists in Microsoft Remote Procedure Call (LRPC). The problem is that an LRPC server may leak the message it receives from the client if the message is of a specific type and has a data view attached (which is not expected for messages of the type). RPC considers this an error and returns, but does not free the message. This allows the client to fill up the address space of the server with such messages.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2014-0316.
Mitigating Factors
Microsoft has not identified any mitigating factors for this vulnerability.
Workarounds
Microsoft has not identified any workarounds for this vulnerability.
FAQ
What is the scope of the vulnerability?
This is a security feature bypass vulnerability.
What causes the vulnerability?
The vulnerability is caused when RPC improperly frees messages that the server rejects as malformed, allowing an attacker to fill up the address space of a process.
What is the component affected by the vulnerability?
The component affected by the vulnerability is Local RPC (LRPC), a component of Microsoft Remote Procedure Call (RPC).
What is Remote Procedure Call (RPC)?
Microsoft Remote Procedure Call (RPC) is an interprocess communications (IPC) mechanism that enables data exchange and invocation of functionality residing in a different process. That process can be on the same computer, on the local area network (LAN), or across the Internet. The Microsoft RPC mechanism uses other IPC mechanisms, such as named pipes, NetBIOS, or Winsock, to establish communications between the client and the server. With RPC, essential program logic and related procedure code can exist on different computers, which is important for distributed applications. For more information, see What Is RPC?
What is LRPC?
Local RPC (LRPC) is a component of Microsoft RPC. LRPC internally uses LPC as the transport mechanism for passing messages between the two processes.
What are Interprocess Communications (IPC)?
Microsoft Windows operating systems provide mechanisms for facilitating communications and data sharing between applications. Collectively, the activities enabled by these mechanisms are called interprocess communications (IPC). Some forms of IPC facilitate the division of labor among several specialized processes. Other forms of IPC facilitate the division of labor among computers on a network. For more information, see Interprocess Communications.
What might an attacker use the vulnerability to do?
In a web-browsing attack scenario, an attacker who successfully exploited this vulnerability could bypass the ASLR security feature, which protects users from a broad class of vulnerabilities. The security feature bypass by itself does not allow arbitrary code execution. However, an attacker could use this ASLR bypass vulnerability in conjunction with another vulnerability, such as a remote code execution vulnerability that could take advantage of the ASLR bypass to run arbitrary code.
How could an attacker exploit the vulnerability?
An attacker could tie this security feature bypass vulnerability to an additional vulnerability, usually a remote code execution vulnerability. The additional vulnerability would take advantage of the security feature bypass for exploitation. For example, a remote code execution vulnerability that is blocked by ASLR, could be exploited after a successful ASLR bypass.
What systems are primarily at risk from the vulnerability?
Both workstations and servers are at risk from this vulnerability.
What does the update do?
The update addresses the vulnerability by correcting how RPC handles the freeing of malformed messages.
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.
Yes, you must restart your system after you apply this security update.
Removal information
To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, and then under Windows Update, click View installed updates and select from the list of updates.
Yes, you must restart your system after you apply this security update.
Removal information
To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, and then under Windows Update, click View installed updates and select from the list of updates.
Yes, you must restart your system after you apply this security update.
Removal information
To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.
Yes, you must restart your system after you apply this security update.
Removal information
To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.
Yes, you must restart your system after you apply this security update.
Removal Information
Click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.
Microsoft thanks the following for working with us to help protect customers:
Alex Ionescu for reporting the LRPC ASLR Bypass Vulnerability (CVE-2014-0316)
Other Information
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
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