Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code. Updates are available.
Description
Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code.
The vulnerability is due to errors when the vulnerable application processes Embedded OpenType (EOT) fonts by the Win32k.sys kernel driver. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious website. If the user visits the site, the attacker could execute arbitrary code with the privileges of the Windows kernel.
Microsoft has confirmed this vulnerability in a security bulletin and released software updates.
Warning Indicators
The following Microsoft systems are affected:
Windows 2000 SP4
Windows XP SP3 and SP2
Windows XP Professional x64 Edition SP2
Windows Server 2003 SP2
Windows Server 2003 x64 Edition SP2
Windows Server 2003 for Itanium-based Systems SP2
IntelliShield Analysis
Attackers cannot directly exploit this vulnerability, and instead must rely on user participation. The attacker must convince the user to view a malicious website, likely by providing links to users within e-mail messages or posted on public websites. If an exploit is successful, the attacker could execute arbitrary code on the vulnerable system. Even systems that restrict user privileges may be at risk of complete compromise, because any code execution would run in the privileged context of the Windows kernel.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the November 2009 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 November 2009
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS09-065
Impact
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with the privileges of the Windows kernel, possibly resulting in a complete system compromise.
Technical Information
The vulnerability is due to errors when the vulnerable application processes EOT fonts by the Win32k.sys kernel driver. EOT fonts may be used in web content. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a web page that contains a malicious embedded font. When processed by the kernel driver, the font could trigger an error condition to enable the attacker to execute code in the privileged security context of the Windows kernel.
Safeguards
Administrators are advised to apply the appropriate updates.
Users should verify that unsolicited links are safe to follow.
Administrators are advised to allow only privileged users to access administration or management systems.
Administrators are advised to monitor critical 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.
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 Windows Update website. 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
Home Edition SP2, SP3 | Professional Edition SP2, SP3 | Professional x64 (AMD/EM64T) SP2
Associated Products:
N/A
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