Microsoft Security Bulletin MS16-084 - Critical

Cumulative Security Update for Internet Explorer (3169991)

Published: July 12, 2016 | Updated: March 17, 2017

Version: 1.1

Executive Summary

This security update resolves vulnerabilities in Internet Explorer. The most severe of the vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited the vulnerabilities could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

This security update is rated Critical for Internet Explorer 9 (IE 9), and Internet Explorer 11 (IE 11) on affected Windows clients, and Moderate for Internet Explorer 9 (IE 9), Internet Explorer 10 (IE 10), and Internet Explorer 11 (IE 11) on affected Windows servers. For more information, see the Affected Software section.

The update addresses the vulnerabilities by:

  • Modifying how Internet Explorer handles objects in memory
  • Modifying how the JScript and VBScript scripting engines handle objects in memory
  • Correcting how the Microsoft Browser XSS Filter validates JavaScript
  • Changing how certain functions in Internet Explorer handle objects in memory
  • Correcting how Internet Explorer parses HTML

For more information about the vulnerabilities, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3169991.

Affected Software

The following software versions or editions are affected. Versions or editions that are not listed 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.

Operating System Component Maximum Security Impact Aggregate Severity Rating Updates Replaced*
Internet Explorer 9
Windows Vista Service Pack 2 Internet Explorer 9
(3170106)
Remote Code Execution Critical 3160005 in MS16-063
Windows Vista x64 Edition Service Pack 2 Internet Explorer 9
(3170106)
Remote Code Execution Critical 3160005 in MS16-063
Windows Server 2008 for 32-bit Systems Service Pack 2 Internet Explorer 9
(3170106)
Remote Code Execution Moderate 3160005 in MS16-063
Windows Server 2008 for x64-based Systems Service Pack 2 Internet Explorer 9
(3170106)
Remote Code Execution Moderate 3160005 in MS16-063
Internet Explorer 10
Windows Server 2012 Internet Explorer 10[1]
(3170106)
Remote Code Execution Moderate 3160005 in MS16-063
Internet Explorer 11
Windows 7 for 32-bit Systems Service Pack 1 Internet Explorer 11 (3170106) Remote Code Execution Critical 3160005 in MS16-063
Windows 7 for x64-based Systems Service Pack 1 Internet Explorer 11 (3170106) Remote Code Execution Critical 3160005 in MS16-063
Windows Server 2008 R2 for x64-based Systems Service Pack 1 Internet Explorer 11[1]
(3170106)
Remote Code Execution Moderate 3160005 in MS16-063
Windows 8.1 for 32-bit Systems Internet Explorer 11 (3170106) Remote Code Execution Critical 3160005 in MS16-063
Windows 8.1 for x64-based Systems Internet Explorer 11 (3170106) Remote Code Execution Critical 3160005 in MS16-063
Windows Server 2012 R2 Internet Explorer 11 (3170106) Remote Code Execution Moderate 3160005 in MS16-063
Windows RT 8.1 Internet Explorer 11[1] [2] (3170106) Remote Code Execution Critical 3160005 in MS16-063
Windows 10 for 32-bit Systems[3] (3163912) Internet Explorer 11 Remote Code Execution Critical 3163017
Windows 10 for x64-based Systems[3] (3163912) Internet Explorer 11 Remote Code Execution Critical 3163017
Windows 10 Version 1511 for 32-bit Systems[3] (3172985) Internet Explorer 11 Remote Code Execution Critical 3163018
Windows 10 Version 1511 for x64-based Systems[3] (3172985) Internet Explorer 11 Remote Code Execution Critical 3163018

[1]For information about changes in support for Internet Explorer beginning January 12, 2016, see Microsoft Support Lifecycle.

[2]This update is available via Windows Update.

[3]Windows 10 updates are cumulative. The monthly security release includes all security fixes for vulnerabilities that affect Windows 10, in addition to non-security updates. The updates are available via the Microsoft Update Catalog.

Note The vulnerabilities discussed in this bulletin affect Windows Server 2016 Technical Preview 4 and Windows Server 2016 Technical Preview 5. An update is available for Windows Server 2016 Technical Preview 5 via Windows Update. However, no update is available for Windows Server 2016 Technical Preview 4. To be protected from the vulnerabilities, Microsoft recommends that customers running Windows Server 2016 Technical Preview 4 upgrade to Windows Server 2016 Technical Preview 5.

*The Updates Replaced column shows only the latest update in any chain of superseded updates. For a comprehensive list of updates replaced, go to the Microsoft Update Catalog, search for the update KB number, and then view update details (updates replaced information is provided on the Package Details tab).

Update FAQ

For my particular system and Internet Explorer configuration, which update addresses the vulnerabilities discussed in CVE-2016-3204? CVE-2016-3204 is a vulnerability in the VBScript engine. Although the attack vector is through Internet Explorer, the vulnerability is addressed by the updates released in this bulletin (MS16-084) for systems running Internet Explorer 9, Internet Explorer 10, and Internet Explorer 11. For Internet Explorer 7 and earlier, the vulnerabilities are addressed by the updates described in MS16-086.

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 July bulletin summary.

Where specified in the Severity Ratings and Impact table, Critical, Important, and Moderate values indicate severity ratings. For more information, see Security Bulletin Severity Rating System. Refer to the following key for the abbreviations used in the table to indicate maximum impact:

Abbreviation Maximum Impact
RCE Remote Code Execution
EoP Elevation of Privilege
ID Information Disclosure
SFB Security Feature Bypass

Vulnerability Severity Ratings and Impact
CVE number Vulnerability title Internet Explorer 9 Internet Explorer 10 Internet Explorer 11 Internet Explorer 11
on Windows 10
CVE-2016-3204 Scripting Engine Memory Corruption Vulnerability Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
CVE-2016-3240 Internet Explorer Memory Corruption Vulnerability Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
CVE-2016-3241 Internet Explorer Memory Corruption Vulnerability Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
CVE-2016-3242 Internet Explorer Memory Corruption Vulnerability Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
CVE-2016-3243 Internet Explorer Memory Corruption Vulnerability Not applicable Windows Clients:
Important / RCE
Windows Servers
Low/ RCE
Windows Clients:
Important / RCE
Windows Servers
Low/ RCE
Windows Clients:
Important / RCE
Windows Servers
Low/ RCE
CVE-2016-3245 Internet Explorer Security Feature Bypass Vulnerability Windows Clients:
Moderate / SFB
Windows Servers
Low / SFB
Windows Clients:
Moderate / SFB
Windows Servers
Low / SFB
Windows Clients:
Moderate / SFB
Windows Servers
Low / SFB
Not applicable
CVE-2016-3248 Scripting Engine Memory Corruption Vulnerability Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate/ RCE
CVE-2016-3259 Scripting Engine Memory Corruption Vulnerability Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
CVE-2016-3260 Scripting Engine Memory Corruption Vulnerability Not applicable Not applicable Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
Windows Clients:
Critical / RCE
Windows Servers
Moderate / RCE
CVE-2016-3261 Internet Explorer Information Disclosure Vulnerability Not applicable Not applicable Windows Clients:
Important / ID
Windows Servers
Low / ID
Windows Clients:
Important / ID
Windows Servers
Low / ID
CVE-2016-3264 Microsoft Browser Memory Corruption Vulnerability Windows Clients:
Critical / RCE
**
Windows Servers:
**Moderate / RCE
Windows Clients:
Critical / RCE
**
Windows Servers:
**Moderate / RCE
Windows Clients:
Critical / RCE
**
Windows Servers:
**Moderate / RCE
Windows Clients:
Critical / RCE
**
Windows Servers:
**Moderate / RCE
CVE-2016-3273 Microsoft Browser Information Disclosure Vulnerability Windows Clients:
Important / ID
Windows Servers
Low / ID
Windows Clients:
Important / ID
Windows Servers
Low / ID
Windows Clients:
Important / ID
Windows Servers
Low / ID
Windows Clients:
Important / ID
Windows Servers
Low / ID
CVE-2016-3274 Microsoft Browser Spoofing Vulnerability Windows Clients:
Moderate / Spoofing
Windows Servers
Low / Spoofing
Windows Clients:
Moderate / Spoofing
Windows Servers
Low / Spoofing
Windows Clients:
Moderate / Spoofing
Windows Servers
Low / Spoofing
Windows Clients:
Moderate / Spoofing
Windows Servers
Low / Spoofing
CVE-2016-3277 Microsoft Browser Information Disclosure Vulnerability Not applicable Windows Clients:
Important / ID
Windows Servers
Low / ID
Windows Clients:
Important / ID
Windows Servers
Low / ID
Windows Clients:
Important / ID
Windows Servers
Low / ID

Vulnerability Information

Multiple Microsoft Internet Explorer Memory Corruption Vulnerabilities

Remote code execution vulnerabilities exist when Internet Explorer improperly accesses objects in memory. The vulnerabilities could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerabilities could gain the same user rights as the current user. If the current user is logged on with administrative user rights, the attacker could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

An attacker could host a specially crafted website that is designed to exploit the vulnerabilities through Internet Explorer, and then convince a user to view the website. The attacker could also take advantage of compromised websites, or websites that accept or host user-provided content or advertisements, by adding specially crafted content that could exploit the vulnerabilities. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically by an enticement in an email or Instant Messenger message, or by getting them to open an attachment sent through email. The update addresses the vulnerabilities by modifying how Internet Explorer handles objects in memory.

The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Internet Explorer Memory Corruption Vulnerability CVE-2016-3240 No No
Internet Explorer Memory Corruption Vulnerability CVE-2016-3241 No No
Internet Explorer Memory Corruption Vulnerability CVE-2016-3242 No No
Internet Explorer Memory Corruption Vulnerability CVE-2016-3243 No No
Microsoft Browser Memory Corruption Vulnerability CVE-2016-3264 No No

Mitigating Factors

Microsoft has not identified any mitigating factors for these vulnerabilities.

Workarounds

Microsoft has not identified any workarounds for these vulnerabilities.

FAQ

I am running Internet Explorer on Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, or Windows Server 2012 R2. Does this mitigate these vulnerabilities?
Yes. By default, Internet Explorer on Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, and Windows Server 2012 R2 runs in a restricted mode that is known as Enhanced Security Configuration. Enhanced Security Configuration is a group of preconfigured settings in Internet Explorer that can reduce the likelihood of a user or administrator downloading and running specially crafted web content on a server. This is a mitigating factor for websites that you have not added to the Internet Explorer Trusted sites zone.

Can EMET help mitigate attacks that attempt to exploit these vulnerabilities?
Yes. The Enhanced Mitigation Experience Toolkit (EMET) enables users to manage security mitigation technologies that help make it more difficult for attackers to exploit memory corruption vulnerabilities in a given piece of software. EMET can help mitigate attacks that attempt to exploit these vulnerabilities in Internet Explorer on systems where EMET is installed and configured to work with Internet Explorer.

For more information about EMET, see the Enhanced Mitigation Experience Toolkit.

Internet Explorer Security Feature Bypass Vulnerability - CVE-2016-3245

A restricted ports security feature bypass vulnerability exists for Internet Explorer. An attacker could take advantage of the vulnerability to trick a user into connecting to a remote system.

To exploit the vulnerability, an attacker would have to either convince a user to visit a malicious website or inject malicious code into a compromised website. The update addresses the vulnerability by correcting how Internet Explorer validates URLs for restricted ports.

The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Internet Explorer Security Feature Bypass Vulnerability CVE-2016-3245 No No

Mitigating Factors

Microsoft has not identified any mitigating factors for this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Multiple Scripting Engine Memory Corruption Vulnerabilities

Multiple remote code execution vulnerabilities exist in the way that the JScript 9 and VBScript engines render when handling objects in memory in Internet Explorer. The vulnerabilities could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerabilities could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerabilities could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerabilities through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites, and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerabilities. The update addresses the vulnerabilities by modifying how the JScript 9 and VBScript scripting engines handle objects in memory.

The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Scripting Engine Memory Corruption Vulnerability CVE-2016-3204 No No
Scripting Engine Memory Corruption Vulnerability CVE-2016-3248 No No
Scripting Engine Memory Corruption Vulnerability CVE-2016-3259 No No
Scripting Engine Memory Corruption Vulnerability CVE-2016-3260 No No

Mitigating Factors

Microsoft has not identified any mitigating factors for these vulnerabilities.

Workarounds

The following workaround may be helpful in your situation:

  • Restrict access to VBScript.dll and JScript.dll

    • For 32-bit systems, enter the following command at an administrative command prompt:
            takeown /f %windir%\system32\vbscript.dll   
            cacls %windir%\system32\vbscript.dll /E /P everyone:N  
            cacls %windir%\system32\jscript.dll /E /P everyone:N          
  • For 64-bit systems, enter the following command at an administrative command prompt:
            takeown /f %windir%\syswow64\vbscript.dll   
            cacls %windir%\syswow64\vbscript.dll /E /P everyone:N  
            cacls %windir%\syswow64\jscript.dll /E /P everyone:N         

Impact of Workaround. Websites that use VBScript or JScript may not work properly.

How to undo the workaround.

  • For 32-bit systems, enter the following command at an administrative command prompt:
            cacls %windir%\system32\vbscript.dll /E /R everyone  
            cacls %windir%\system32\jscript.dll /E /R everyone          
  • For 64-bit systems, enter the following command at an administrative command prompt:
            cacls %windir%\syswow64\vbscript.dll /E /R everyone  
            cacls %windir%\syswow64\jscript.dll /E /R everyone          

Multiple Internet Explorer Information Disclosure Vulnerabilities

Information disclosure vulnerabilities exist when the Microsoft Browser improperly handles objects in memory. An attacker who successfully exploited the vulnerabilities could obtain information to further compromise the user’s system.

To exploit the vulnerabilities, in a web-based attack scenario, an attacker could host a website that is used to attempt to exploit the vulnerabilities. In addition, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could exploit the vulnerabilities. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action. For example, an attacker could trick users into clicking a link that takes them to the attacker's site. The update addresses the vulnerabilities by changing how certain functions handle objects in memory.

The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Internet Explorer Information Disclosure Vulnerability CVE-2016-3261 No No
Microsoft Browser Information Disclosure Vulnerability CVE-2016-3277 No No

Mitigating Factors

Microsoft has not identified any mitigating factors for these vulnerabilities.

Workarounds

Microsoft has not identified any workarounds for these vulnerabilities.

Microsoft Browser Information Disclosure Vulnerability - CVE-2016-3273

An information disclosure vulnerability exists when the Microsoft Browser XSS Filter does not properly validate content under specific conditions. An attacker who exploited the vulnerability could run arbitrary JavaScript that could lead to an information disclosure.

In a web-based attack scenario, an attacker could host a website in an attempt to exploit this vulnerability. In addition, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could exploit the vulnerability.

However, in all cases an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action. For example, an attacker could trick users into clicking a link that takes the user to the attacker's site. The update addresses the vulnerability by correcting how the Microsoft Browser XSS Filter validates content.

The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Microsoft Browser Information Disclosure Vulnerability CVE-2016-3273 No No

Mitigating Factors

Microsoft has not identified any mitigating factors for this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Microsoft Browser Spoofing Vulnerability – CVE-2016-3274

A spoofing vulnerability exists when a Microsoft browser does not properly parse HTTP content. An attacker who successfully exploited this vulnerability could trick a user by redirecting the user to a specially crafted website. The specially crafted website could either spoof content or serve as a pivot to chain an attack with other vulnerabilities in web services.

To exploit the vulnerability, the user must click a specially crafted URL. In an email attack scenario, an attacker could send an email message containing the specially crafted URL to the user in an attempt to convince the user to click it.

In a web-based attack scenario, an attacker could host a specially crafted website designed to appear as a legitimate website to the user. However, the attacker would have no way to force the user to visit the specially crafted website. The attacker would have to convince the user to visit the specially crafted website, typically by way of enticement in an email or Instant Messenger message, and then convince the user to interact with content on the website. The update addresses the vulnerability by correcting how the Microsoft browser parses HTTP responses.

The following table contains links to the standard entry for each vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Microsoft Browser Spoofing Vulnerability CVE-2016-3274 No No

Mitigating Factors

Microsoft has not identified any mitigating factors for this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Security Update Deployment

For Security Update Deployment information see the Microsoft Knowledge Base article referenced here in the Executive Summary.

Acknowledgments

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgments for more information.

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 (July 12, 2016): Bulletin published.
  • V1.1 (March 17, 2017): Removed CVE-2016-3276 from the Vulnerability Severity Ratings and Impact table and from the Vulnerability Information because Internet Explorer 9, Internet Explorer 10, and Internet Explorer 11 are not affected by this vulnerability. This is an informational change only.

Page generated 2017-03-17 14:08-07:00.