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                              CERT-Renater

                  Note d'Information No. 2015/VULN182
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DATE                : 09/09/2015

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Windows version 8.1, 10, Server 2012 running
                                    Windows Hyper-V.

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KB3091287
https://technet.microsoft.com/en-us/library/security/MS15-105
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Microsoft Security Bulletin MS15-105: Important Vulnerability in Windows 
Hyper-V Could Allow Security Feature Bypass (3091287)

Bulletin Number: MS15-105

Bulletin Title: Important Vulnerability in Important  Could Allow 
Security Feature Bypass

Severity: Important

KB Article: 3091287

Version: 1.0

Published Date: September 8, 2015

Executive Summary

This security update resolves a vulnerability in Microsoft Windows. The
vulnerability could allow security feature bypass if an attacker runs a
specially crafted application that could cause Windows Hyper-V to
incorrectly apply access control list (ACL) configuration settings.
Customers who have not enabled the Hyper-V role are not affected.

This security update is rated Important for all supported editions of
Windows 8.1 for x64-based Systems, Windows Server 2012 R2, and Windows
10 for x64-based Systems. For more information, see the Affected
Software section.


Affected Software

Windows 8.1 for x64-based Systems

Windows Server 2012 R2

Windows 10 for x64-based Systems[1]

Server Core installation option

Windows Server 2012 R2 (Server Core installation)

[1]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.


Vulnerability Information


Hyper-V Security Feature Bypass Vulnerability - CVE-2015-2534

A security feature bypass vulnerability exists in Windows Hyper-V when
access control list (ACL) configuration settings are not applied
correctly. To exploit the vulnerability, an attacker could run a
specially crafted application that could cause Hyper-V to allow
unintended network traffic. Customers who have not enabled the Hyper-V
role are not affected. The security update addresses the vulnerability
by correcting how Hyper-V applies ACL configuration settings.

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.

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https://services.renater.fr/ssi/
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