CVE-2002-1156 in HTTP Server
Summary
by MITRE
Apache 2.0.42 allows remote attackers to view the source code of a CGI script via a POST request to a directory with both WebDAV and CGI enabled.
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability described in CVE-2002-1156 represents a critical security flaw in the Apache HTTP Server version 2.0.42 that enables remote attackers to access sensitive source code files through a specific request pattern. This issue arises from the improper handling of WebDAV and CGI module interactions within the web server configuration, creating an unintended pathway for information disclosure that could compromise the confidentiality of server-side applications. The vulnerability specifically manifests when both WebDAV and CGI capabilities are enabled simultaneously on the same directory, allowing attackers to exploit this configuration weakness through a carefully crafted POST request.
The technical root cause of this vulnerability stems from the way Apache processes requests when both WebDAV and CGI modules are active in the same directory context. When a POST request is sent to a directory that has both modules enabled, the server fails to properly validate or restrict access to the underlying CGI script files, allowing the attacker to retrieve the source code of these scripts through the WebDAV interface. This occurs because the WebDAV module does not adequately enforce the same access controls that would normally prevent unauthorized access to sensitive files, particularly when CGI scripts are present in the same directory. The flaw essentially creates a bypass mechanism where WebDAV operations can inadvertently expose the source code of CGI programs, which often contain sensitive information such as database credentials, application logic, and other proprietary code elements.
The operational impact of CVE-2002-1156 extends beyond simple information disclosure, as the exposure of CGI script source code can provide attackers with detailed insights into application architecture, database connection parameters, and potential attack vectors within the web application. This information can be leveraged to conduct more sophisticated attacks such as SQL injection, cross-site scripting, or privilege escalation attempts. The vulnerability affects systems where administrators have enabled both WebDAV and CGI capabilities on the same directory structure, which was a common configuration in early apache deployments. This flaw particularly impacts organizations running legacy web applications where the WebDAV module was enabled for collaborative document management while CGI scripts were used for dynamic content generation. The vulnerability is classified under CWE-200 Information Disclosure, which specifically addresses the exposure of sensitive information through improper access control mechanisms, and aligns with ATT&CK technique T1566.001 for credential access through web application vulnerabilities.
Organizations affected by this vulnerability should immediately implement multiple mitigation strategies to address the security risk. The primary recommendation involves disabling either the WebDAV or CGI module on directories where both are enabled simultaneously, as the combination creates the exploitable condition. Additionally, administrators should ensure that CGI scripts are placed in directories that do not have WebDAV enabled, and vice versa. Configuration changes should include proper access controls and directory permissions that prevent unauthorized access to script source files. The vulnerability also highlights the importance of regular security audits and the principle of least privilege in web server configurations. System administrators should review their Apache configurations to ensure that modules are not enabled unnecessarily and that proper security controls are in place to prevent cross-module exploitation. This vulnerability serves as a reminder of the critical importance of understanding how different server modules interact and the potential for unintended security consequences when multiple modules are enabled simultaneously. The security community should also consider implementing automated scanning tools to identify similar configuration weaknesses in web server deployments, as this type of cross-module vulnerability can often go unnoticed during routine security assessments.
This vulnerability demonstrates the complex nature of modern web server security where interactions between different modules can create unexpected attack surfaces. The flaw represents a classic example of how seemingly benign configuration choices can lead to significant security implications, particularly when modules designed for different purposes are enabled in the same context. The attack vector is relatively simple and can be executed remotely without requiring authentication, making it particularly dangerous for publicly accessible web servers. The vulnerability also underscores the importance of keeping web server software up to date with the latest security patches, as Apache 2.0.42 was an older version that contained this specific flaw. Organizations should implement comprehensive security policies that include regular vulnerability assessments, proper configuration management, and monitoring for unusual access patterns that might indicate exploitation attempts. The incident also highlights the need for security awareness training for system administrators to understand the implications of combining different server capabilities and the potential risks associated with such configurations.