CVE-2002-0654 in HTTP Server
Summary
by MITRE
Apache 2.0 through 2.0.39 on Windows, OS2, and Netware allows remote attackers to determine the full pathname of the server via (1) a request for a .var file, which leaks the pathname in the resulting error message, or (2) via an error message that occurs when a script (child process) cannot be invoked.
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Analysis
by VulDB Data Team • 09/14/2025
This vulnerability affects Apache HTTP Server versions 2.0 through 2.0.39 when deployed on Windows, OS/2, and Netware operating systems. The issue stems from insufficient input validation and error handling mechanisms within the server's file processing logic. Attackers can exploit this weakness to gain information about the server's directory structure through specifically crafted requests that trigger error responses containing sensitive path information.
The vulnerability manifests in two primary attack vectors that leverage the server's error reporting mechanisms. The first vector involves requesting a .var file extension, which causes the server to generate an error message containing the full server pathname in the response. The second vector occurs when the server attempts to execute a script or child process that cannot be invoked, resulting in an error message that inadvertently reveals the complete file path. Both attack methods exploit the server's tendency to include absolute path information in error messages for debugging purposes.
From a cybersecurity perspective, this vulnerability represents a classic information disclosure weakness that aligns with CWE-200, which describes the improper handling of sensitive information in software applications. The flaw enables attackers to gather reconnaissance data about the target system's file structure, which can significantly aid in planning more sophisticated attacks. The information leakage occurs without requiring authentication or special privileges, making it particularly dangerous as it can be exploited by anyone with network access to the affected server.
The operational impact of this vulnerability extends beyond simple information disclosure. An attacker who successfully exploits this weakness can use the leaked path information to craft more targeted attacks against the server's file system. This includes identifying sensitive directories, understanding the server's configuration structure, and potentially locating other vulnerabilities that may exist within the application's file handling mechanisms. The vulnerability is particularly concerning in environments where Apache serves dynamic content through various scripting languages or modules that rely on specific file paths for execution.
Mitigation strategies for this vulnerability should focus on implementing proper error handling and input validation within the Apache server configuration. System administrators should ensure that error messages do not contain sensitive path information by configuring appropriate error reporting levels. The recommended approach involves modifying the server's configuration to suppress detailed error messages that reveal file system information. Additionally, upgrading to Apache versions beyond 2.0.39 resolves this vulnerability, as subsequent releases implemented enhanced security measures to prevent path leakage in error responses. Organizations should also implement network segmentation and access controls to limit exposure to this specific attack vector while maintaining comprehensive monitoring of server error logs for potential exploitation attempts.
This vulnerability demonstrates the importance of secure coding practices in web server implementations and aligns with ATT&CK technique T1212, which covers exploitation of information disclosure vulnerabilities. The attack pattern represents a fundamental security flaw that violates the principle of least privilege by exposing system internals through error handling mechanisms. Security professionals should consider this vulnerability when conducting penetration testing and vulnerability assessments, particularly in legacy Apache installations where upgrading may not be immediately feasible. The issue also highlights the need for regular security audits of web server configurations to ensure that default settings do not inadvertently expose sensitive system information to potential attackers.