CVE-2004-2090 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 5.0.1 through 6.0 allows remote attackers to determine the existence of arbitrary files via the VBScript LoadPicture method, which returns an error code if the file does not exist.
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Analysis
by VulDB Data Team • 09/16/2025
This vulnerability resides in Microsoft Internet Explorer versions 5.0.1 through 6.0 and represents a classic information disclosure flaw that leverages the VBScript LoadPicture method to reveal file system information. The vulnerability stems from the way Internet Explorer handles file existence checks through scripting interfaces, specifically when the LoadPicture method encounters files that do not exist on the target system. When attackers exploit this weakness, they can craft malicious web pages that attempt to load non-existent images or other media files, and the resulting error codes provide indirect but valuable information about the target system's file structure. This behavior creates a side-channel attack vector where the error response can be interpreted to determine whether specific files or directories exist, effectively allowing attackers to map parts of the file system without direct access to the underlying operating system.
The technical implementation of this vulnerability occurs within the VBScript engine integrated into Internet Explorer, where the LoadPicture method is designed to load image files into memory for display purposes. When the method attempts to load a file that does not exist, it returns specific error codes that can be captured and analyzed by malicious scripts. This error handling mechanism becomes exploitable when combined with automated testing techniques that systematically attempt to load various file paths and observe the responses. The vulnerability is particularly dangerous because it operates within the browser's scripting environment, making it accessible through standard web page delivery mechanisms without requiring special privileges or direct system access. The flaw essentially exposes the underlying file system structure through the error reporting mechanism, creating a reconnaissance opportunity for attackers to gather intelligence about target systems.
From an operational perspective, this vulnerability enables attackers to perform systematic reconnaissance against target systems by determining the existence of specific files or directories, which can lead to further exploitation opportunities. Attackers can use this information to identify sensitive files, system configuration details, or application-specific resources that may contain exploitable vulnerabilities or valuable data. The impact extends beyond simple reconnaissance as it provides attackers with actionable intelligence that can be used in subsequent attacks, such as identifying potential targets for privilege escalation or exploiting other vulnerabilities that may be present on the system. This type of information disclosure vulnerability is classified under CWE-209, which specifically addresses the exposure of error information that could aid in system exploitation. The vulnerability also aligns with ATT&CK technique T1083, which covers the discovery of file and directory permissions, as the ability to determine file existence effectively reveals information about file system structure and potentially access patterns.
The exploitation of this vulnerability requires minimal technical sophistication and can be automated using standard web scripting techniques. Attackers can create web pages that systematically test for the existence of common system files, application directories, or sensitive configuration files, using the error codes returned by the LoadPicture method as indicators of success or failure. The vulnerability affects a broad range of Internet Explorer versions, making it particularly dangerous as it could impact numerous systems that had not yet been updated with security patches. Organizations running these older browser versions were particularly vulnerable to this type of attack, as the vulnerability was not addressed in the mainstream security updates for these legacy browsers. The threat landscape was further complicated by the fact that many organizations continued to use these outdated browsers for extended periods, creating persistent attack surfaces that could be exploited without requiring complex attack chains or specialized tools. Mitigation strategies included updating to patched versions of Internet Explorer, implementing browser security policies that restricted VBScript execution, and deploying network-level controls to detect and block malicious web content that attempted to exploit this vulnerability.