CVE-2005-0063 in Windows
Summary
by MITRE
The document processing application used by the Windows Shell in Microsoft Windows 2000, Windows XP, and Windows Server 2003 allows remote attackers to execute arbitrary code by modifying the CLSID stored in a file so that it is processed by HTML Application Host (MSHTA), as demonstrated using a Microsoft Word document.
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Analysis
by VulDB Data Team • 07/05/2025
The vulnerability described in CVE-2005-0063 represents a critical security flaw in Microsoft Windows operating systems that affects Windows 2000, Windows XP, and Windows Server 2003. This issue stems from how the Windows Shell processes document files, particularly those that contain embedded component object model (COM) identifiers known as CLSIDs. The vulnerability operates through a sophisticated attack vector that leverages the interaction between different Windows components and the HTML Application Host (MSHTA) process, creating a pathway for remote code execution that could be exploited by malicious actors without user interaction.
The technical flaw lies in the improper handling of CLSIDs within file metadata that are processed by the Windows Shell. When a user opens a specially crafted document such as a Microsoft Word file, the system attempts to resolve the CLSID stored within the document's metadata. The vulnerability occurs because the Windows Shell does not properly validate or sanitize these CLSIDs before attempting to execute them through the MSHTA application host. This allows attackers to manipulate the CLSID to point to malicious code that gets executed within the context of the MSHTA process, which runs with elevated privileges. The attack demonstrates a classic example of a component-based attack where a seemingly benign document can be transformed into a delivery mechanism for malicious payloads through manipulation of embedded identifiers.
The operational impact of this vulnerability is severe as it enables remote code execution without requiring user interaction, making it particularly dangerous in enterprise environments. Attackers can craft malicious documents that, when opened by unsuspecting users, automatically execute malicious code on the target system. This vulnerability affects the core Windows Shell functionality and can lead to complete system compromise, allowing attackers to install backdoors, steal sensitive data, or establish persistent access to compromised systems. The vulnerability is particularly concerning because it operates at the system level through the Windows Shell and MSHTA components, which are fundamental to normal Windows operation, making it difficult to detect and prevent through traditional security measures.
This vulnerability aligns with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-78 (Improper Neutralization of Special Elements used in OS Command Injection) in the Common Weakness Enumeration catalog, as it involves improper handling of component identifiers and command execution. From the MITRE ATT&CK framework perspective, this vulnerability maps to techniques such as T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter), specifically leveraging the Windows Shell and MSHTA for remote code execution. The attack chain typically involves initial compromise through social engineering or drive-by downloads, followed by exploitation of the CLSID manipulation technique to execute malicious payloads. Organizations should implement immediate mitigations including disabling MSHTA execution, implementing proper file validation, and applying security updates. Network segmentation and monitoring for suspicious file execution patterns can help detect exploitation attempts, while user education about avoiding suspicious documents remains crucial in preventing successful exploitation of this vulnerability.