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                           CERT-Renater

               Note d'Information No. 2015/VULN074
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DATE                : 13/05/2015

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running .NET Framework.

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KB3057134
https://technet.microsoft.com/en-us/library/security/MS15-048
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MS15-048: Vulnerabilities in .NET Framework Could Allow Elevation of
Privilege (3057134)

Bulletin Number: MS15-048

Bulletin Title: Vulnerabilities in .NET Framework Could Allow Elevation
of Privilege

Severity: Important

KB Article: 3057134

Version: 1.0

Published Date: May 12, 2015

Executive Summary

This security update resolves vulnerabilities in Microsoft .NET
Framework. The most severe of the vulnerabilities could allow elevation
of privilege if a user installs a specially crafted partial trust
application.

This security update is rated Important for Microsoft .NET Framework
1.1 Service Pack 1, Microsoft .NET Framework 2.0 Service Pack 2,
Microsoft .NET Framework 3.5, Microsoft .NET Framework 3.5.1, Microsoft
.NET Framework 4, Microsoft .NET Framework 4.5, Microsoft .NET
Framework 4.5.1, and Microsoft .NET Framework 4.5.2 on affected
releases of Microsoft Windows. For more information, see the Affected
Software section.


Affected Software

Windows Server 2003 Service Pack 2

Windows Server 2003 x64 Edition Service Pack 2

Windows Server 2003 with SP2 for Itanium-based Systems

Windows Vista Service Pack 2

Windows Vista x64 Edition Service Pack 2

Windows Server 2008 for 32-bit Systems Service Pack 2

Windows Server 2008 for x64-based Systems Service Pack 2

Windows Server 2008 for Itanium-based Systems Service Pack 2

Windows 7 for 32-bit Systems Service Pack 1

Windows 7 for x64-based Systems Service Pack 1

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

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

Windows 8 for 32-bit Systems

Windows 8 for x64-based Systems

Windows 8.1 for 32-bit Systems

Windows 8.1 for x64-based Systems

Windows Server 2012

Windows Server 2012 R2

Windows RT

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

Windows Server 2012 (Server Core installation)

Windows Server 2012 R2 (Server Core installation)

[1].NET Framework 4 and .NET Framework 4 Client Profile affected.

[2]This update is available via Windows Update only.


Vulnerability Information

.NET XML Decryption Denial of Service Vulnerability - CVE-2015-1672

A denial of service vulnerability exists in Microsoft .NET Framework
that could allow an unauthenticated attacker to degrade the performance
of a .NET-enabled website and disrupt the availability of applications
that use Microsoft .NET Framework. The vulnerability exists when
Microsoft .NET Framework attempts to decrypt certain specially crafted
XML data.

To exploit this vulnerability, an attacker could send specially crafted
XML data to a .NET application with the intention of causing processing
recursion that leads to the denial-of-service condition. Servers
running affected versions of Microsoft .NET Framework are primarily at
risk from this vulnerability. The update addresses the vulnerability by
correcting how the .NET Framework decrypts XML data.

Microsoft received information about this vulnerability through
coordinated vulnerability disclosure. When this security bulletin was
issued, Microsoft had not received any information to indicate that
this vulnerability had been publicly used to attack customers.


Windows Forms Elevation of Privilege Vulnerability - CVE-2015-1673

An elevation of privilege vulnerability exists in Microsoft .NET
Framework that is caused when .NETs Windows Forms (WinForms) libraries
improperly handle objects in memory. An attacker who successfully
exploited the vulnerability 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. Users whose
accounts are configured to have fewer user rights on the system could
be less impacted than users who operate with administrative user rights.

To exploit this vulnerability, an attacker could use social engineering
tactics to lure a user into installing a specially crafted partial
trust application. Workstations and servers that run partial-trust .NET
Framework applications are primarily at risk from this vulnerability.
The update addresses the vulnerability by correcting how .NET Framework
handles objects in memory.

Microsoft received information about this vulnerability through
coordinated vulnerability disclosure. When this security bulletin was
issued, Microsoft had not received any information to indicate that
this vulnerability had been publicly used to attack customers.


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