Microsoft .NET Framework contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system.
The vulnerability is due to insufficient boundary checks on user-supplied data processed by the .NET Framework. An unauthenticated, remote attacker could exploit the vulnerability by convincing a user to visit a malicious website. If successful, the attacker could execute arbitrary code on the system with the privileges of the user.
Microsoft confirmed the vulnerability in a security bulletin and released software updates.
Indicators of Compromise
Microsoft .NET Framework versions 2.0 SP2 and 3.5.1 are vulnerable when running on the following systems:
Windows XP SP3 and prior
Windows XP Professional x64 Edition SP2 and prior
Windows Server 2003 SP2 and prior
Windows Server 2003 x64 Edition SP2 and prior
Windows Vista SP2 and prior
Windows Vista x64 Edition SP2 and prior
Windows Server 2008 for 32-bit Systems SP2 and prior
Windows Server 2008 for x64-based Systems SP2 and prior
The vulnerability is due to insufficient boundary checks on user-supplied data processed by the .NET Framework. The component fails to validate overly large values before using data in memory operations.
An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a website that contains a malicious embedded .NET application. When processed, data from the application could cause the .NET Framework to store overly large values in memory, causing heap corruption that the attacker could leverage to execute arbitrary code on the system.
To exploit the vulnerability, the attacker may provide a link that directs a user to a malicious site and use misleading language or instructions to persuade the user to follow the provided link.
Administrators are advised to apply the appropriate updates.
Users are advised not to open e-mail messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in e-mail messages are safe, they are advised not to open them.
Administrators may consider disabling XAML browser applications in Internet Explorer.
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.
Microsoft has released a security bulletin at the following link: MS12-016
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 Windows Update website. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.