Microsoft Security Bulletin MS15-018 - Critical

• 10/11/2017
• 21 minutes to read

Cumulative Security Update for Internet Explorer (3032359)

Published: March 10, 2015

Version: 1.0

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 6 (IE 6), 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 6 (IE 6), 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 modifying the way that Internet Explorer handles objects in memory, by modifying how the VBScript scripting engine handles objects in memory, by helping to ensure that cross-domain policies are properly enforced in Internet Explorer, and by adding additional permission validations to Internet Explorer. For more information about the vulnerabilities, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3032359.

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 

Note For systems running Internet Explorer 8 or later, CVE-2015-0032 is addressed by this update (3032359). For all other affected versions of Internet Explorer, CVE-2015-0032 is addressed by the update described in MS15-019. For more information, see the Update FAQ.

Note Windows Technical Preview and Windows Server Technical Preview are affected. Customers running these operating systems are encouraged to apply the update, which is available via Windows Update. 

Update FAQ

For addressing CVE-2015-0032, what update applies to my system?  CVE-2015-0032 is a vulnerability in the VBScript scripting engine. Although the attack vector is through Internet Explorer, this vulnerability is addressed by this update (3032359) only for systems running Internet Explorer 8, Internet Explorer 9, Internet Explorer 10, and Internet Explorer 11. For Internet Explorer 7 and earlier and for systems without Internet Explorer installed, this vulnerability is addressed by the update described in MS15-019.

The update that addresses CVE-2015-0032 depends on the version of the VBScript scripting engine that is installed on your system. Consult the following table for update information.

**Are there additional updates for Internet Explorer that I should be aware of?  **Yes. There is an additional fix for Internet Explorer 11 that is included as part of update 3032359.

For Internet Explorer 11 on Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1:

• If you have not installed security update 3021952 (See Microsoft Security Bulletin MS15-009), when you install update 3032359, update 3023607 will also be installed automatically. Update 3023607 changes Transport Layer Security (TLS) protocol renegotiation and fallback behavior.
• When installation is complete, updates 3032359 and 3023607 will be listed in Installed Updates.
• If you download and install updates manually, when you click Download you will be prompted to select updates 3032359 and 3023607. If you have installed security update 3021952, you do not need to reinstall update 3023607.
• For more information, see Microsoft Knowledge Base Article 3023607.

For Internet Explorer 11 on Windows 8.1, Windows Server 2012 R2, and Windows RT 8.1:

• When you install update 3032359, update 3040335 will be installed automatically. Update 3040335 changes TLS protocol renegotiation and fallback behavior. Update 3040335 also supercedes update 3023607 to resolve issues with various VPN software applications.
• When installation is complete, updates 3032359 and 3040335 will be listed in Installed Updates.
• If you download and install updates manually, when you click Download you will be prompted to select updates 3032359 and 3040335.
• For more information, see Microsoft Knowledge Base Article 3040335.

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 March 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:

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. The update addresses the vulnerabilities by modifying the way that Internet Explorer handles objects in memory.

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 complete 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 the way that 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: