Microsoft Security Bulletin MS15-094 - Critical

  • Article
  • 19 minutes to read

Cumulative Security Update for Internet Explorer (3089548)

Published: September 8, 2015 | Updated: December 13, 2016

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 these 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 those who operate with administrative user rights.

This security update is rated Critical for Internet Explorer 7 (IE 7), Internet Explorer 8 (IE 8), Internet Explorer 9 (IE 9), Internet Explorer 10 (IE 10), and Internet Explorer 11 (IE 11) on affected Windows clients, and Moderate for Internet Explorer 7 (IE 7), Internet Explorer 8 (IE 8), 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 security update addresses the vulnerabilities by:

  1. Modifying how Internet Explorer handles objects in memory
  2. Modifying how Internet Explorer, JScript, and VBScript handle objects in memory
  3. Helping to ensure that Internet Explorer correctly permits file operations

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

For more information about this update, see Microsoft Knowledge Base Article 3089548.

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.

Affected Software 

**Operating System** **Component** **Maximum Security Impact** **Aggregate Severity Rating** **Updates Replaced**\*
**Internet Explorer 7**
Windows Vista Service Pack 2 [Internet Explorer 7](https://www.microsoft.com/download/details.aspx?familyid=5ba12849-024a-4cd0-8905-321b5b76dea2)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Vista x64 Edition Service Pack 2 [Internet Explorer 7](https://www.microsoft.com/download/details.aspx?familyid=d398a7c8-155e-43eb-b272-5b862bcb6232)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for 32-bit Systems Service Pack 2 [Internet Explorer 7](https://www.microsoft.com/download/details.aspx?familyid=fae5069f-cdc7-4d21-8a03-792333df71b1)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for x64-based Systems Service Pack 2 [Internet Explorer 7](https://www.microsoft.com/download/details.aspx?familyid=f3790f0d-ebd9-4e99-b716-cd3f7a4b5f63)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for Itanium-based Systems Service Pack 2 [Internet Explorer 7](https://www.microsoft.com/download/details.aspx?familyid=24633264-aa8b-436e-bbc8-ec0c932b99fb)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
**Internet Explorer 8**
Windows Vista Service Pack 2 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=4e0c6abf-83ae-4057-982d-325c220776d1)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Vista x64 Edition Service Pack 2 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=daf0452a-7067-4945-84a9-eef0e5f63fba)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for 32-bit Systems Service Pack 2 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=a614f217-72b1-4676-8309-60cd50427ed8)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for x64-based Systems Service Pack 2 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=de261c95-0c03-4221-a9b1-7609d5492107)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 7 for 32-bit Systems Service Pack 1 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=db8d057d-32c2-4719-a4ff-3b5360337b33)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 7 for x64-based Systems Service Pack 1 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=00bff054-0e1a-4f9a-b09d-57ee5c67024a)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 R2 for x64-based Systems Service Pack 1 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=45531ad7-b2a8-49c8-8451-52a7002cacca)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 R2 for Itanium-based Systems Service Pack 1 [Internet Explorer 8](https://www.microsoft.com/download/details.aspx?familyid=796cfd42-8114-40df-a168-989e137b992f)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
**Internet Explorer 9**
Windows Vista Service Pack 2 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=386866c0-de27-4dbe-aa94-acd0fd739db1)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Vista x64 Edition Service Pack 2 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=363bdabf-703e-4f1c-bc40-83b708b2a1e5)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for 32-bit Systems Service Pack 2 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=b8e43491-0abf-4b12-828e-4d19a27165b9)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 for x64-based Systems Service Pack 2 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=d8f33b76-1ddf-492d-8f57-233e042e4054)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 7 for 32-bit Systems Service Pack 1 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=fe95931e-d04a-4b0d-974d-27946391004c)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 7 for x64-based Systems Service Pack 1 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=92ec76b4-1fd4-412d-8ffd-b5ed6fd2b281)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 R2 for x64-based Systems Service Pack 1 [Internet Explorer 9](https://www.microsoft.com/download/details.aspx?familyid=c0dc507c-6867-4c64-97d2-ec073e18adae)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
**Internet Explorer 10**
Windows 7 for 32-bit Systems Service Pack 1 [Internet Explorer 10](https://www.microsoft.com/download/details.aspx?familyid=2af1ab9b-5687-4565-8df1-ace69fdaa112)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 7 for x64-based Systems Service Pack 1 [Internet Explorer 10](https://www.microsoft.com/download/details.aspx?familyid=04c9ef46-93b7-415f-a1b5-6c1683a5815e)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 R2 for x64-based Systems Service Pack 1 [Internet Explorer 10](https://www.microsoft.com/download/details.aspx?familyid=3edc274f-45be-423c-b602-3195c2a11276)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 8 for 32-bit Systems [Internet Explorer 10](https://www.microsoft.com/download/details.aspx?familyid=40f903f7-8973-465d-8820-691539c5010a)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 8 for x64-based Systems [Internet Explorer 10](https://www.microsoft.com/download/details.aspx?familyid=2aa5db91-39d7-4a1c-939b-f6fed7b3ebb9)  (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2012 [Internet Explorer 10](https://www.microsoft.com/download/details.aspx?familyid=0a33f314-e59e-4bb2-89bf-de2cd288beb3)  (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows RT Internet Explorer 10[1] (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
**Internet Explorer 11**
Windows 7 for 32-bit Systems Service Pack 1 [Internet Explorer 11](https://www.microsoft.com/download/details.aspx?familyid=b72d441b-185c-46d8-bdc2-f4ab246a519b) (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 7 for x64-based Systems Service Pack 1 [Internet Explorer 11](https://www.microsoft.com/download/details.aspx?familyid=07b63b8e-acca-4c05-8833-5ea5ddaaed19) (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2008 R2 for x64-based Systems Service Pack 1 [Internet Explorer 11](https://www.microsoft.com/download/details.aspx?familyid=14fd1b4d-93f8-49a2-b634-b8f7d1eb5b69) (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 8.1 for 32-bit Systems [Internet Explorer 11](https://www.microsoft.com/download/details.aspx?familyid=05e56d45-caf5-40e0-a336-932be747a139) (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows 8.1 for x64-based Systems [Internet Explorer 11](https://www.microsoft.com/download/details.aspx?familyid=3b08f9e7-ed27-4259-b0b9-704fa4adc2bc) (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows Server 2012 R2 [Internet Explorer 11](https://www.microsoft.com/download/details.aspx?familyid=c5444f2b-ba1a-4938-b515-db247577d6cd) (3087038) Remote Code Execution Moderate 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
Windows RT 8.1 Internet Explorer 11[1] (3087038) Remote Code Execution Critical 3087985 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
[Windows 10 for 32-bit Systems](https://support.microsoft.com/kb/3081455)[2] (3081455) Internet Explorer 11 Remote Code Execution Critical 3081444 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
[Windows 10 for x64-based Systems](https://support.microsoft.com/kb/3081455)[2] (3081455) Internet Explorer 11 Remote Code Execution Critical 3081444 in [MS15-093](http://go.microsoft.com/fwlink/?linkid=620908)
[1]This update is available via [Windows Update](http://go.microsoft.com/fwlink/?linkid=21130).

[2]The Windows 10 update is cumulative. In addition to containing non-security updates, it also contains all of the security fixes for all of the Windows 10-affected vulnerabilities shipping with this month’s security release. See Microsoft Knowledge Base Article 3081444 for more information and download links.

*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).

Note Windows Server Technical Preview 2 and Windows Server Technical Preview 3 are affected. Customers running this operating system are encouraged to apply the update, which is available via Windows Update. 

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 September 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 7** **Internet Explorer 8** **Internet Explorer 9** **Internet Explorer 10** **Internet Explorer 11** **Internet Explorer 11 on Windows 10**
[CVE-2015-2483](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2483) Information Disclosure Vulnerability Not applicable Not applicable Not applicable Windows Clients: **Important / ID** Windows Servers: **Low / ID** Windows Clients: **Important / ID** Windows Servers: **Low / ID** Not applicable
[CVE-2015-2484](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2484) Tampering Vulnerability Not applicable Not applicable 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**
[CVE-2015-2485](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2485) Memory Corruption Vulnerability Not applicable Not applicable 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-2015-2486](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2486) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE**
[CVE-2015-2487](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2487) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable
[CVE-2015-2489](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2489) Elevation of Privilege Vulnerability Not applicable Not applicable Not applicable Not applicable Windows Clients: **Important / EoP** Windows Servers: **Low / EoP** Windows Clients: **Important / EoP** Windows Servers: **Low / EoP**
[CVE-2015-2490](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2490) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable
[CVE-2015-2491](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2491) Memory Corruption Vulnerability Not applicable Not applicable Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable
[CVE-2015-2492](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2492) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE**
[CVE-2015-2493](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2493) Scripting Engine Memory Corruption Vulnerability Not applicable Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable Not applicable Not applicable Not applicable
[CVE-2015-2494](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2494) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE**
[CVE-2015-2496](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2496) Information Disclosure Vulnerability Windows Clients: **Moderate / ID** Windows Servers: **Low / ID** Windows Clients: **Moderate / ID** Windows Servers: **Low / ID** Windows Clients: **Moderate / ID** Windows Servers: **Low / ID** Windows Clients: **Moderate / ID** Windows Servers: **Low / ID** Windows Clients: **Moderate / ID** Windows Servers: **Low / ID** Windows Clients: **Moderate / ID** Windows Servers: **Low / ID**
[CVE-2015-2498](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2498) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE**
[CVE-2015-2499](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2499) 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** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE**
[CVE-2015-2500](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2500) Memory Corruption Vulnerability Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable Not applicable Not applicable Not applicable
[CVE-2015-2501](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2501) Memory Corruption Vulnerability Not applicable Not applicable Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable Not applicable Not applicable
[CVE-2015-2541](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2541) Memory Corruption Vulnerability Not applicable Not applicable Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Windows Clients: **Critical / RCE** Windows Servers: **Moderate / RCE** Not applicable
[CVE-2015-2542](http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=cve-2015-2542) Memory Corruption Vulnerability Not applicable Not applicable Not applicable Windows Clients: **Important / RCE** Windows Servers: **Important / RCE** Windows Clients: **Important / RCE** Windows Servers: **Important / RCE** Windows Clients: **Important / RCE** Windows Servers: **Important / RCE**

 Vulnerability Information

Multiple Memory Corruption Vulnerabilities in Internet Explorer

Remote code execution vulnerabilities exist when Internet Explorer improperly accesses objects in memory. These vulnerabilities could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user.

An attacker could host a specially crafted website that is designed to exploit these vulnerabilities through Internet Explorer, 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 these 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 getting them to click a link in an instant messenger or email message that takes users to the attacker's website, or by getting them to open an attachment sent through email.

An attacker who successfully exploited these 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 these 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. Systems where Internet Explorer is used frequently, such as workstations or terminal servers, are at the most risk from these vulnerabilities.

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
Memory Corruption Vulnerability CVE-2015-2485 No No
Memory Corruption Vulnerability CVE-2015-2486 No No
Memory Corruption Vulnerability CVE-2015-2487 No No
Memory Corruption Vulnerability CVE-2015-2490 No No
Memory Corruption Vulnerability CVE-2015-2491 No No
Memory Corruption Vulnerability CVE-2015-2492 No No
Memory Corruption Vulnerability CVE-2015-2494 No No
Memory Corruption Vulnerability CVE-2015-2498 No No
Memory Corruption Vulnerability CVE-2015-2499 No No
Memory Corruption Vulnerability CVE-2015-2500 No No
Memory Corruption Vulnerability CVE-2015-2501 No No
Memory Corruption Vulnerability CVE-2015-2541 No No
Memory Corruption Vulnerability CVE-2015-2542 Yes No
### Mitigating Factors Microsoft has not identified any [mitigating factors](https://technet.microsoft.com/library/security/dn848375.aspx) for these vulnerabilities. ### Workarounds Microsoft has not identified any [workarounds](https://technet.microsoft.com/library/security/dn848375.aspx) 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](http://technet.microsoft.com/library/dd883248). 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](http://technet.microsoft.com/security/jj653751). Scripting Engine Memory Corruption Vulnerability – CVE-2015-2493 ---------------------------------------------------------------- A remote code execution vulnerability exists in the way that the VBScript and JScript engines, when rendered in Internet Explorer, handle objects in memory. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability 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 vulnerability. An attacker who successfully exploited the vulnerability 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 vulnerability 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. The update addresses the vulnerability by modifying how the VBScript and JScript scripting engines handle objects in memory. Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was originally issued, Microsoft had not received any information to indicate that the vulnerability had been publicly used to attack customers.

Vulnerability title CVE number Publicly disclosed Exploited
Scripting Engine Memory Corruption Vulnerability CVE-2015-2493 No No
  ### Mitigating Factors Microsoft has not identified any [mitigating factors](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. ### Workarounds The following [workarounds](https://technet.microsoft.com/library/security/dn848375.aspx) 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

Elevation of Privilege Vulnerability – CVE-2015-2489

An elevation of privilege vulnerability exists when Internet Explorer does not properly validate permissions under specific conditions, potentially allowing a script to be run with elevated privileges.

In a web-based attack scenario, an attacker could host a website that is used to 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 this vulnerability. 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. An attacker who successfully exploited the vulnerability could elevate privileges in affected versions of Internet Explorer.

The vulnerability by itself does not allow arbitrary code to be run. However, the vulnerability could be used in conjunction with another vulnerability (e.g., a remote code execution vulnerability) that could take advantage of the elevated privileges when running arbitrary code. For example, an attacker could exploit another vulnerability to run arbitrary code through Internet Explorer, but due to the context in which processes are launched by Internet Explorer, the code might be restricted to run at a low integrity level (very limited permissions). However, an attacker could, in turn, exploit the vulnerability to cause the arbitrary code to run at a medium integrity level (permissions of the current user).

The update addresses the vulnerability by adding additional permission validations to Internet Explorer. The following table contains links to the standard entry for the vulnerability in the Common Vulnerabilities and Exposures list:

Vulnerability title CVE number Publicly disclosed Exploited
Elevation of Privilege Vulnerability CVE-2015-2489 No No
### Mitigating Factors Microsoft has not identified any [mitigating factors](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. ### Workarounds Microsoft has not identified any [workarounds](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. Information Disclosure Vulnerability – CVE-2015-2483 ---------------------------------------------------- An information disclosure vulnerability exists when Internet Explorer improperly discloses the contents of its memory, which could provide an attacker with information to further compromise the user’s computer. The update addresses the vulnerability by changing the way 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
Information Disclosure Vulnerability CVE-2015-2483 No No
### Mitigating Factors Microsoft has not identified any [mitigating factors](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. ### Workarounds Microsoft has not identified any [workarounds](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. Information Disclosure Vulnerability – CVE-2015-2496 ---------------------------------------------------- An information disclosure vulnerability exists in the way that certain functions handle objects in memory. The vulnerability could allow an attacker to detect specific files on the user's computer. In a web-based attack scenario an attacker could host a website that is used to attempt to exploit the vulnerabilities. Additionally, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could be used to exploit the vulnerabilities. However, in all cases an attacker would have no way to force users to view 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 security update addresses the vulnerability by correcting 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
Information Disclosure Vulnerability CVE-2015-2496 Yes Yes
### Mitigating Factors Microsoft has not identified any [mitigating factors](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. ### Workarounds Microsoft has not identified any [workarounds](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. Tampering Vulnerability – CVE-2015-2484 --------------------------------------- A tampering vulnerability exists when Internet Explorer accesses a file with an improper flag that in turn permits a file operation. This could allow a low privilege process to delete arbitrary files on the local system. This update addresses the vulnerability by properly masking this flag off. 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
Tampering Vulnerability CVE-2015-2484 No No
### Mitigating Factors Microsoft has not identified any [mitigating factors](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. ### Workarounds Microsoft has not identified any [workarounds](https://technet.microsoft.com/library/security/dn848375.aspx) for this vulnerability. Security Update Deployment -------------------------- For Security Update Deployment information see the Microsoft Knowledge Base article referenced 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](https://technet.microsoft.com/library/security/dn903755.aspx) 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 (September 8, 2015): Bulletin published. - V1.1 (December 13, 2016): Bulletin revised to include an additional vulnerability, CVE-2015-2496. This is an informational change only. Customers who have successfully installed the updates do not need to take any further action. *Page generated 2016-12-12 16:16-08:00.*