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.
This vulnerability exists due to insufficient sanitization of name tables by the Embedded OpenType Font Engine when processing content containing embedded fonts. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious website. If the user views the site, the attacker could execute arbitrary code with the privileges of the user.
Microsoft has confirmed this vulnerability in a security bulletin and released updated software.
Warning Indicators
The following Microsoft products are affected:
Windows 2000 SP4 and prior
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 Server 2003 for Itanium-based Systems 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
Windows Server 2008 for Itanium-based Systems SP2 and prior
IntelliShield Analysis
An attacker cannot directly exploit this vulnerability and instead must rely upon user participation in order to accomplish an exploit. Attackers may embed malicious content on public websites in order to launch exploits against users who may access the site. Attackers may also send links within e-mail messages that direct users to malicious sites.
End-user workstations and terminal servers that allow users to run programs with elevated privileges are most at risk. An exploit against a system on which users hold elevated privileges could result in a complete compromise.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the July 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 for July 2009
The update available from Microsoft corrects this vulnerability by improving the parsing of embedded font files.
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS09-029
Impact
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with the privileges of the user. If that user holds elevated privileges, the attacker could completely compromise the vulnerable system.
Technical Information
This vulnerability exists due to insufficient sanitization of name tables by the Embedded OpenType Font Engine when processing content containing embedded fonts. The processing of malicious values within content could trigger an integer overflow, resulting in memory corruption.
An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious website. When parsed, content containing malicious embedded fonts could trigger memory corruption. The attacker could leverage the memory corruption to execute arbitrary code with the privileges of the user.
Safeguards
Administrators are advised to apply the available software updates.
Administrators may consider disabling embedded fonts in Internet Explorer.
Administrators may consider unregistering or preventing access to the t2embed.dll component.
Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.
Users are advised to run applications with the least necessary privileges.
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
Datacenter Edition Base | Datacenter Edition, 64-bit Base | Enterprise Edition Base | Enterprise Edition, 64-bit Base | Essential Business Server Premium Base | Essential Business Server Premium, 64-bit Base | Essential Business Server Standard Base | Itanium-Based Systems Edition Base | Standard Edition Base | Standard Edition, 64-bit Base | Web Server Base | Web Server, 64-bit Base
Microsoft, Inc.
Windows Vista
Business Base, SP1 | Business x64 Edition Base, SP1 | Enterprise Base, SP1 | Enterprise x64 Edition Base, SP1 | Home Basic Base, SP1 | Home Basic x64 Edition Base, SP1 | Home Premium Base, SP1 | Home Premium x64 Edition Base, SP1 | Ultimate Base, SP1 | Ultimate x64 Edition Base, SP1
Microsoft, Inc.
Windows XP
Home Edition Base, SP1, SP2, SP3 | Professional Edition Base, SP1, SP2, SP3 | Professional x64 (AMD/EM64T) Base, SP2
Associated Products:
N/A
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