CVE-2003-0306 in Windows
Summary
by MITRE
Buffer overflow in EXPLORER.EXE on Windows XP allows attackers to execute arbitrary code as the XP user via a desktop.ini file with a long .ShellClassInfo parameter.
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Analysis
by VulDB Data Team • 02/16/2025
The vulnerability identified as CVE-2003-0306 represents a critical buffer overflow flaw within the Windows XP operating system's explorer.exe process. This issue specifically manifests when the system processes desktop.ini configuration files that contain excessively long .ShellClassInfo parameters. The vulnerability resides in the way Windows XP handles shell extensions and file system metadata, creating an exploitable condition that can be leveraged by malicious actors to execute arbitrary code with the privileges of the currently logged-in user. The attack vector is particularly insidious because it requires no special privileges to initiate and can be triggered simply by a user viewing a directory containing the malicious desktop.ini file.
The technical exploitation of this vulnerability stems from improper input validation within the explorer.exe component responsible for parsing shell class information. When a desktop.ini file contains a .ShellClassInfo parameter exceeding the allocated buffer size, the system fails to properly handle the overflow condition, leading to memory corruption that can be manipulated to redirect program execution. This flaw aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability is classified as a stack-based buffer overflow in the context of Windows shell processing, making it particularly dangerous as it occurs within the core operating system components that users interact with daily.
The operational impact of CVE-2003-0306 extends beyond simple code execution, as successful exploitation can result in complete system compromise when combined with other attack vectors. An attacker who successfully exploits this vulnerability can execute malicious code with the privileges of the target user, potentially leading to privilege escalation, data theft, or persistent access to the compromised system. The vulnerability's accessibility makes it a prime target for automated exploitation campaigns, as it requires minimal user interaction beyond normal file system navigation. This characteristic aligns with ATT&CK technique T1059, which describes the execution of malicious code through legitimate system processes, and T1068, which involves local privilege escalation through vulnerable system components.
Mitigation strategies for this vulnerability should prioritize immediate patching through Microsoft's security updates, as the flaw was addressed in subsequent Windows XP service packs and security rollups. Organizations should implement strict file system access controls and monitor for unauthorized modifications to desktop.ini files in user directories. Network administrators should consider implementing application whitelisting policies to prevent execution of untrusted code from potentially compromised shell extensions. Additionally, user education regarding the dangers of opening files from untrusted sources remains crucial, as the vulnerability can be triggered through social engineering attacks that deliver malicious desktop.ini files through email attachments or compromised websites. The vulnerability demonstrates the critical importance of maintaining up-to-date system patches and proper input validation in operating system components, particularly those handling user-provided data in shell extensions and file system metadata processing.