Microsoft Security Bulletin MS15-096 - Important

Vulnerability in Active Directory Service Could Allow Denial of Service (3072595)

Published: September 8, 2015

Version: 1.0

This security update resolves a vulnerability in Active Directory. The vulnerability could allow denial of service if an authenticated attacker creates multiple machine accounts. To exploit the vulnerability an attacker must have an account that has privileges to join machines to the domain.

This security update is rated Important for all supported editions of Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, and Windows Server 2012 R2. For more information, see the Affected Software section.

The security update addresses the vulnerability by correcting by correcting how machine accounts are created. For more information about the vulnerability, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3072595.

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

Maximum Security Impact

Aggregate Severity Rating

Updates Replaced*

Windows Server 2008

Windows Server 2008 for 32-bit Systems Service Pack 2
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2008 for x64-based Systems Service Pack 2
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2008 for Itanium-based Systems Service Pack 2
(3072595)

Denial of Service

Important

None

Windows Server 2008 R2

Windows Server 2008 R2 for x64-based Systems Service Pack 1
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
(3072595)

Denial of Service

Important

None

Windows Server 2012

Windows Server 2012
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2012 R2

Windows Server 2012 R2
(3072595)

Denial of Service

Important

2923392 in MS14-016

Server Core installation option

Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2012 (Server Core installation)
(3072595)

Denial of Service

Important

2923392 in MS14-016

Windows Server 2012 R2 (Server Core installation)
(3072595)

Denial of Service

Important

2923392 in MS14-016

*The Updates Replaced column shows only the latest update in a 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 on the Package Details tab).

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.

Vulnerability Severity Rating and Maximum Security Impact by Affected Software

Affected Software

Active Directory Denial of Service Vulnerability - CVE-2015-2535

Aggregate Severity Rating

Windows Server 2008

Windows Server 2008 for 32-bit Systems Service Pack 2
(3072595)

Important 
Denial of Service

Important

Windows Server 2008 for x64-based Systems Service Pack 2
(3072595)

Important 
Denial of Service

Important

Windows Server 2008 for Itanium-based Systems Service Pack 2
(3072595)

Important 
Denial of Service

Important

Windows Server 2008 R2

Windows Server 2008 R2 for x64-based Systems Service Pack 1
(3072595)

Important 
Denial of Service

Important

Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
(3072595)

Important 
Denial of Service

Important

Windows Server 2012

Windows Server 2012
(3072595)

Important 
Denial of Service

Important

Windows Server 2012 R2
(3072595)

Important 
Denial of Service

Important

Server Core installation option

Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
(3072595)

Important 
Denial of Service

Important

Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
(3072595)

Important 
Denial of Service

Important

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
(3072595)

Important 
Denial of Service

Important

Windows Server 2012 (Server Core installation)
(3072595)

Important 
Denial of Service

Important

Windows Server 2012 R2 (Server Core installation)
(3072595)

Important 
Denial of Service

Important

Active Directory Denial of Service Vulnerability - CVE-2015-2535

A denial of service vulnerability exists in Active Directory when an authenticated attacker creates multiple machine accounts. An attacker who successfully exploited this vulnerability could cause the Active Directory service to become non-responsive.

To exploit this vulnerability an attacker must have valid credentials. An attacker could exploit this vulnerability by creating multiple machine accounts, resulting in denial of service. The update addresses the vulnerability by correcting how machine accounts are created.

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 this vulnerability had been publicly used to attack customers.

Mitigating Factors

The following mitigating factors may apply in your situation:

  • To exploit this vulnerability, an attacker must have an account that has privileges to join machines to the domain. If an attacker cannot join new machines to the domain, the vulnerability cannot be exploited.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

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

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

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.

  • V1.0 (September 8, 2015): Bulletin published.

Page generated 2015-09-02 10:05-07:00.
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