Microsoft Security Bulletin MS16-114 - Important

• 10/11/2017
• 7 minutes to read
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Security Update for Windows SMBv1 Server (3185879)

Published: September 13, 2016

Version: 1.0

Executive Summary

This security update resolves a vulnerability in Microsoft Windows. On Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2 operating systems, the vulnerability could allow remote code execution if an authenticated attacker sends specially crafted packets to an affected Microsoft Server Message Block 1.0 (SMBv1) Server. The vulnerability does not impact other SMB Server versions. Although later operating systems are affected, the potential impact is denial of service.

This security update is rated Important for all supported releases of Microsoft Windows. For more information, see the Affected Software and Vulnerability Severity Ratings section.

The security update addresses the vulnerability by correcting how the Microsoft SMBv1 Server handles specially crafted requests. For more information about the vulnerability, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3185879.

Affected Software and Vulnerability Severity Ratings

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.

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.

^[2]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 update is available via the Windows Update Catalog.

Note The vulnerability discussed in this bulletin affects Windows Server 2016 Technical Preview 5. To be protected from the vulnerability, Microsoft recommends that customers running this operating system apply the current update, which is available from Windows Update. 

*The Updates Replaced column shows only the latest update in any chain of superseded updates.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).

Vulnerability Information

Windows SMB Authenticated Remote Code Execution Vulnerability – CVE-2016-3345

For Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2 operating systems a remote code execution vulnerability exists in the way that the Microsoft Server Message Block 1.0 (SMBv1) Server handles certain requests when an authenticated attacker sends specially crafted packets to the SMBv1 server. The vulnerability does not impact other SMB Server versions.

On later operating systems an attacker who successfully exploited this vulnerability could cause the affected system to stop responding until it is manually restarted.

To exploit the vulnerability an attacker would first need to authenticate to the SMBv1 Server and have permission to open files on the target server before attempting the attack.

The security update addresses the vulnerability by correcting how the Microsoft SMBv1 Server handles specially crafted requests.

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