Microsoft .NET Framework contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
Description
Microsoft .NET Framework contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
The vulnerability is due to improper sanitization when the Windows Communication Foundation (WCF) Replace function processes crafted values. An unauthenticated, remote attacker could exploit this vulnerability by sending malicious requests to a targeted system. If successful, the attacker could cause a DoS condition on the system.
Microsoft confirmed the vulnerability in a security bulletin and released software updates.
Warning Indicators
Microsoft .NET Framework 3.5, 3.5 SP1, 3.5.1, and 4 are vulnerable when running on the following systems:
Windows XP SP3
Windows XP Professional x64 Edition SP2
Windows Server 2003 SP2
Windows Server 2003 x64 Edition SP2
Windows Server 2003 with SP2 for Itanium-based Systems
Windows Vista SP2
Windows Vista x64 Edition SP2
Windows Server 2008 for 32-bit Systems SP2
Windows Server 2008 for x64-based Systems SP2
Windows Server 2008 for Itanium-based Systems SP2
Windows 7 for 32-bit Systems SP1 and prior
Windows 7 for x64-based Systems SP1 and prior
Windows Server 2008 R2 for x64-based Systems SP1 and prior
Windows Server 2008 R2 for Itanium-based Systems SP1 and prior
Windows 8 for 32-bit Systems
Windows 8 for x64-based Systems
Windows Server 2012
IntelliShield Analysis
To exploit the vulnerability, an attacker would need to send malicious HTTP requests to the targeted system. To achieve this objective, the attacker may require access to trusted, internal networks to send malicious requests to the affected system, which could limit the likelihood of a successful exploit.
Microsoft has corrected this vulnerability by turning off the WCF Replace function by default.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the January 2013 security bulletin release. This Cisco bulletin, which assists administrators in identifying or mitigating these vulnerabilities using Cisco devices, is available at the following link: Cisco Applied Mitigation Bulletin: Microsoft Security Bulletin Release for January 2013
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS13-007
Impact
An unauthenticated, remote attacker could exploit this vulnerability to cause the affected software to stop responding to legitimate requests and restart, resulting in a DoS condition.
Technical Information
The vulnerability is due to improper sanitization of crafted values processed by the WCF Replace function of the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by sending crafted HTTP requests to an affected site. Processing the requests could allow the replication of data by the Open Data (OData) protocol used by the WCF Replace function. Exhaustion of system resources could result, causing a DoS condition.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
Administrators are advised to monitor affected systems.
Patches/Software
Microsoft customers can obtain updates directly by using the links in the security bulletin. These updates are also distributed by Windows automatic update features and available on the Microsoft Update service. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.
Signatures
Cisco Systems Cisco Intrusion Prevention System (IPS) 6.0
Datacenter Edition SP2 | Datacenter Edition, 64-bit SP2 | Enterprise Edition SP2 | Enterprise Edition, 64-bit SP2 | Essential Business Server Premium SP2 | Essential Business Server Premium, 64-bit SP2 | Essential Business Server Standard SP2 | Itanium-Based Systems Edition SP2 | Standard Edition SP2 | Standard Edition, 64-bit SP2 | Web Server SP2 | Web Server, 64-bit SP2
Microsoft, Inc.
Windows Server 2008 R2
Itanium-Based Systems Edition Base, SP1 | x64-Based Systems Edition Base, SP1
Microsoft, Inc.
Windows Server 2012
Original Release Base
Microsoft, Inc.
Windows Vista
Business SP2 | Business x64 Edition SP2 | Enterprise SP2 | Enterprise x64 Edition SP2 | Home Basic SP2 | Home Basic x64 Edition SP2 | Home Premium SP2 | Home Premium x64 Edition SP2 | Ultimate SP2 | Ultimate x64 Edition SP2
Microsoft, Inc.
Windows XP
Home Edition SP3 | Media Center Edition SP3 | Professional Edition SP3 | Professional x64 (AMD/EM64T) SP2 | Tablet PC Edition SP3
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