Microsoft Security Bulletin MS16-096 - Critical
Cumulative Security Update for Microsoft Edge (3177358)
Published: August 9, 2016
Version: 1.0
Executive Summary
This security update resolves vulnerabilities in Microsoft Edge. The most severe of the vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Microsoft Edge. An attacker who successfully exploited the vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than users with administrative user rights.
This security update is rated Critical for Microsoft Edge on Windows 10. For more information, see the Affected Software section.
The update addresses the vulnerabilities by:
- Modifying how Microsoft Edge handles objects in memory
- Modifying how the Chakra JavaScript scripting engine handles objects in memory
For more information about the vulnerabilities, see the Vulnerability Information section.
For more information about this update, see Microsoft Knowledge Base Article 3177358.
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** |
**Microsoft Edge** | ||||
[Windows 10 for 32-bit Systems](https://support.microsoft.com/kb/3176492)[1] (3176492) | Microsoft Edge | Remote Code Execution | Critical | [3163912](https://support.microsoft.com/kb/3163912) |
[Windows 10 for x64-based Systems](https://support.microsoft.com/kb/3176492)[1] (3176492) | Microsoft Edge | Remote Code Execution | Critical | [3163912](https://support.microsoft.com/kb/3163912) |
[Windows 10 Version 1511 for 32-bit Systems](https://support.microsoft.com/kb/3176493)[1] (3176493) | Microsoft Edge | Remote Code Execution | Critical | [3172985](https://support.microsoft.com/kb/3172985) |
[Windows 10 Version 1511 for x64-based Systems](https://support.microsoft.com/kb/3176493)[1] (3176493) | Microsoft Edge | Remote Code Execution | Critical | [3172985](https://support.microsoft.com/kb/3172985) |
[Windows 10 Version 1607 for 32-bit Systems](https://support.microsoft.com/kb/3176495)[1] (3176495) | Microsoft Edge | Remote Code Execution | Critical | None |
[Windows 10 Version 1607 for x64-based Systems](https://support.microsoft.com/kb/3176495)[1] (3176495) | Microsoft Edge | Remote Code Execution | Critical | None |
Note The vulnerabilities discussed in this bulletin affect Windows Server 2016 Technical Preview 5. To be protected from the vulnerabilities, Microsoft recommends that customers running this operating system apply the current update, which is available exclusively from Windows Update.
Update FAQ
Does this update contain any additional security-related changes to functionality?
Yes. With the release of this update, RC4 encryption will be disabled in Internet Explorer 11 and Edge browsers, in keeping with industry security standards. For more information, see Microsoft Knowledge Base Article 3151631.
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.
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** | **Microsoft Edge** |
[CVE-2016-3289](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3289) | Microsoft Browser Memory Corruption Vulnerability | Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** |
[CVE-2016-3293](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3293) | Microsoft Browser Memory Corruption Vulnerability | Windows Clients: **Important / RCE** Windows Servers: **Low / RCE** |
[CVE-2016-3296](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3296) | Scripting Engine Memory Corruption Vulnerability | Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** |
[CVE-2016-3319](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3319) | Microsoft PDF Remote Code Execution Vulnerability | Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** |
[CVE-2016-3322](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3322) | Microsoft Browser Memory Corruption Vulnerability | Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** |
[CVE-2016-3326](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3326) | Microsoft Browser Information Disclosure Vulnerability | Windows Clients: **Important / ID** Windows Servers **Low / ID** |
[CVE-2016-3327](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3327) | Microsoft Browser Information Disclosure Vulnerability | Windows Clients: **Important / ID** Windows Servers **Low / ID** |
[CVE-2016-3329](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2016-3329) | Microsoft Browser Information Disclosure Vulnerability | Windows Clients: **Moderate / ID** Windows Servers **Low / ID** |
Vulnerability Information
Multiple Microsoft Edge Memory Corruption Vulnerabilities
Multiple remote code execution vulnerabilities exist when Microsoft Edge improperly accesses objects in memory. The vulnerabilities could corrupt memory in a way that enables an attacker to 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 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 Microsoft Edge, and then convince a user to view the website. The attacker could also take advantage of compromised websites and 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 way of an enticement in an email or instant message, or by getting them to open an email attachment. The update addresses the vulnerabilities by modifying how Microsoft Edge 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 |
Microsoft Browser Memory Corruption Vulnerability | CVE-2016-3289 | No | No |
Microsoft Browser Memory Corruption Vulnerability | CVE-2016-3293 | No | No |
Microsoft PDF Remote Code Execution Vulnerability | CVE-2016-3319 | No | No |
Microsoft Browser Memory Corruption Vulnerability | CVE-2016-3322 | No | No |
Vulnerability title | CVE number | Publicly disclosed | Exploited |
Scripting Engine Memory Corruption Vulnerability | CVE-2016-3296 | No | No |
Vulnerability title | CVE number | Publicly disclosed | Exploited |
Microsoft Browser Information Disclosure Vulnerability | CVE-2016-3326 | No | No |
Microsoft Browser Information Disclosure Vulnerability | CVE-2016-3327 | No | No |
Vulnerability title | CVE number | Publicly disclosed | Exploited |
Microsoft Browser Information Disclosure Vulnerability | CVE-2016-3329 | No | No |