Microsoft Security Bulletin MS14-050 - Important
Vulnerability in Microsoft SharePoint Server Could Allow Elevation of Privilege (2977202)
Published: August 12, 2014
Version: 1.0
General Information
Executive Summary
This security update resolves one privately reported vulnerability in Microsoft SharePoint Server. An authenticated attacker who successfully exploited this vulnerability could use a specially crafted app to run arbitrary JavaScript in the context of the user on the current SharePoint site.
This security update is rated Important for supported editions of Microsoft SharePoint Server 2013 and Microsoft SharePoint Foundation 2013. For more information, see the Affected and Non-Affected Software section.
The security update addresses the vulnerability by correcting how SharePoint Server sanitizes specially crafted applications (apps) that use custom actions. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability later in this bulletin.
Recommendation. Customers can configure automatic updating to check online for updates from Microsoft Update by using the Microsoft Update service. Customers who have automatic updating enabled and configured to check online for updates from Microsoft Update typically 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 from Microsoft Update 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.
Note for SharePoint Server The detection tools (such as Microsoft Update, WSUS, MBSA, SMS, and System Center Configuration Manager) are applicable for single-server Microsoft SharePoint Server deployments. The detection tools do not detect the applicability of the updates on systems configured as part of a multiple-system SharePoint server farm. For recommended instructions on how to apply updates to SharePoint Server, see Deploy software updates for SharePoint 2013.
Knowledge Base Article
- Knowledge Base Article: 2977202
- File Information: Yes
- SHA1/SHA2 hashes: Yes
- Known issues: Yes
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 Server Software
| Software | Component | Maximum Security Impact | Aggregate Severity Rating | Updates Replaced |
|---|---|---|---|---|
| Microsoft Windows SharePoint Server | ||||
| Microsoft SharePoint Server 2013 | Microsoft SharePoint Server 2013 (2880994) | Elevation of Privilege | Important | 2863856 in MS14-022 |
| Microsoft SharePoint Server 2013 Service Pack 1 | Microsoft SharePoint Server 2013 Service Pack 1 (2880994) | Elevation of Privilege | Important | 2863856 in MS14-022 |
| Microsoft SharePoint Server 2013 | Microsoft SharePoint Foundation 2013 (2880994) | Elevation of Privilege | Important | 2863856 in MS14-022 |
| Microsoft SharePoint Server 2013 Service Pack 1 | Microsoft SharePoint Foundation 2013 Service Pack 1 (2880994) | Elevation of Privilege | Important | 2863856 in MS14-022 |
Non-Affected Software
| Software |
|---|
| Microsoft SharePoint Portal Server 2003 Service Pack 3 |
| Microsoft SharePoint Server 2007 Service Pack 3 (32-bit edition) |
| Microsoft SharePoint Server 2007 Service Pack 3 (64-bit edition) |
| Excel Services on Microsoft SharePoint Server 2007 Service Pack 3 (32-bit editions) |
| Excel Services on Microsoft SharePoint Server 2007 Service Pack 3 (64-bit editions) |
| Microsoft Windows SharePoint Services 2.0 |
| Microsoft Windows SharePoint Services 3.0 Service Pack 3 (32-bit versions) |
| Microsoft Windows SharePoint Services 3.0 Service Pack 3 (64-bit versions) |
| Microsoft SharePoint Foundation 2010 Service Pack 1 |
| Microsoft SharePoint Foundation 2010 Service Pack 2 |
| Excel Services on Microsoft SharePoint Server 2010 Service Pack 1 |
| Excel Services on Microsoft SharePoint Server 2010 Service Pack 2 |
| Word Automation Services on Microsoft SharePoint Server 2010 Service Pack 1 |
| Word Automation Services on Microsoft SharePoint Server 2010 Service Pack 2 |
| Microsoft Web Applications 2010 Service Pack 1 |
| Microsoft Web Applications 2010 Service Pack 2 |
| Microsoft Excel Web App 2010 Service Pack 1 |
| Microsoft Excel Web App 2010 Service Pack 2 |
Update FAQ
What if an app stops working or does not install properly after installing this update?
Because this update corrects how SharePoint sanitizes apps, some apps, particularly those that use custom actions, may stop working or not install properly after installing this update. Evaluate apps that stop working or that do not install properly on a case-by-case basis. If the app is from an untrusted source or is no longer needed, you should remove the app. For more information about removing apps, see Remove app for SharePoint instances from a SharePoint 2013 site. Warning After you remove an app, you will not be able to recover any data that the app may be storing in the location where it is hosted. If you want to keep this data, you must save it before you remove the app. Go to the app you plan to remove, and manually copy the data to another format (some apps may provide you with a way to export data).
On the other hand, if the app is one you trust and want to keep using, check trusted sources or contact the app author for an updated version that functions and installs correctly.
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 , 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.
Microsoft Server Software
| Vulnerability Severity Rating and Maximum Security Impact by Affected Software | ||
|---|---|---|
| Affected Software | SharePoint Page Content Vulnerability - CVE-2014-2816 | Aggregate Severity Rating |
| Microsoft Windows SharePoint Server 2013 | ||
| Microsoft SharePoint Server 2013 | Important Elevation of Privilege | Important |
| Microsoft SharePoint Server 2013 Service Pack 1 | Important Elevation of Privilege | Important |
| Microsoft SharePoint Foundation 2013 | Important Elevation of Privilege | Important |
| Microsoft SharePoint Foundation 2013 Service Pack 1 | Important Elevation of Privilege | Important |
SharePoint Page Content Vulnerability - CVE-2014-2816
An elevation of privilege vulnerability exists in SharePoint Server. An authenticated attacker who successfully exploited this vulnerability could use a specially crafted app to run arbitrary code in the security context of the logged-on user.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2014-2816.
Mitigating Factors
Microsoft has not identified any mitigating factors for this 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:
For SharePoint instances, evaluate and remove apps as appropriate. Install new apps from trusted sources only.
Evaluate installed apps on a case-by-case basis and remove those that were installed from untrusted sources and those that are not needed anymore. You should also evaluate apps installed from trusted sources to see if the app has been removed from the trusted source. If an app has been removed from the trusted source, this may be an indication that the app is now considered untrusted and you should remove the app from your SharePoint instances.For more information, see Remove app for SharePoint instances from a SharePoint 2013 site.
After removing apps installed from untrusted sources, install new apps as needed from trusted sources only.
Impact of workaround When administrators remove apps for SharePoint from SharePoint sites, the apps are uninstalled and functionality is no longer available to users.
Warning After you remove an app, you will not be able to recover any data that the app may be storing in the location where it is hosted. If you want to keep this data, you must save it before you remove the app. Go to the app you plan to remove, and manually copy the data to another format (some apps may provide you with a way to export data).
FAQ
What is the scope of the vulnerability?
This is an elevation of privilege vulnerability.
What causes the vulnerability?
The vulnerability is caused when SharePoint Server does not properly handle a specially crafted app that uses the SharePoint extensibility model to execute arbitrary JavaScript on behalf of the user. Conditions exist where an app could bypass app permission management and run arbitrary code in the security context of the logged-on user.
What is app permissions management?
The purpose of app permissions management is to manage the ability of apps to access and use internal SharePoint 2013 resources and perform tasks on behalf of users. For more information, see Plan app permissions management in SharePoint 2013.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited the vulnerability could use a specially crafted app to execute arbitrary script in the security context of the logged-on user. The script could then, for example, take actions on the affected SharePoint site on behalf of the logged-on user with the same permissions as the logged-on user.
How could an attacker exploit the vulnerability?
An attacker could create a specially crafted app designed to exploit this vulnerability, and then convince users to install the specially crafted app.
What systems are primarily at risk from the vulnerability?
Systems running an affected version of SharePoint Server that allow connections from apps that implement the affected feature set are primarily at risk.
What does the update do?
The update addresses the vulnerability by correcting how SharePoint Server sanitizes specially crafted apps that use custom actions.
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 were 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.
Note for SharePoint Server The detection tools (such as Microsoft Update, WSUS, MBSA, SMS, and System Center Configuration Manager) are applicable for single-server Microsoft SharePoint Server deployments. The detection tools do not detect the applicability of the updates on systems configured as part of a multiple-system SharePoint server farm. For recommended instructions on how to apply updates to SharePoint Server, see Deploy software updates for SharePoint 2013.
Security Update Deployment
SharePoint Server 2013 (all editions) and SharePoint Foundation 2013 (all versions)
Reference Table
The following table contains the security update information for this software.
| Security update file name | For Microsoft SharePoint Server 2013 and Microsoft SharePoint Foundation 2013:\ sts2013-kb2880994-fullfile-x64-glb.exe |
|---|---|
| Installation switches | See Microsoft Knowledge Base Article 912203 |
| Restart requirement | In some cases, this update does not require a restart. If the required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart.\ \ To help reduce the chance that a restart will be required, stop all affected services and close all applications that may use the affected files prior to installing the security update. For more information about the reasons why you may be prompted to restart, see Microsoft Knowledge Base Article 887012. |
| Removal information | This security update cannot be removed. |
| File information | For Microsoft SharePoint Server 2013 and Microsoft SharePoint Foundation 2013:\ Microsoft Knowledge Base Article 2880994 |
| Registry key verification | Not applicable |
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
- 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 (August 12, 2014): Bulletin published.
Page generated 2014-08-06 16:54Z-07:00.