CVE-2004-2019 in PHP-Nuke
Summary
by MITRE
The WebLinks module in Php-Nuke 6.x through 7.3 allows remote attackers to obtain sensitive information via an invalid show parameter, which displays the full path in a PHP error message.
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Analysis
by VulDB Data Team • 06/25/2018
The vulnerability described in CVE-2004-2019 represents a classic information disclosure flaw within the WebLinks module of Php-Nuke versions 6.x through 7.3. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-provided parameters before processing them within the application's code execution flow. The vulnerability specifically manifests when an attacker supplies an invalid show parameter to the WebLinks module, which triggers PHP's error handling mechanism to display detailed error messages containing the full server path information. This type of vulnerability falls under the category of CWE-200 - Information Exposure, where sensitive system information is inadvertently exposed to unauthorized users through error messages.
The technical implementation of this vulnerability exploits the fundamental weakness in parameter validation within the WebLinks module's processing logic. When the system receives an invalid show parameter, the application fails to implement proper error handling or input sanitization, allowing PHP's default error reporting to expose the complete file path where the script is executing. This occurs because the module does not validate whether the show parameter contains expected values or properly handle unexpected inputs through exception management. The exposed path information can include the complete directory structure of the web server installation, potentially revealing sensitive details about the hosting environment, file locations, and system configuration that could aid attackers in subsequent exploitation attempts.
The operational impact of this vulnerability extends beyond simple information disclosure, as the leaked path information provides attackers with crucial reconnaissance data for planning more sophisticated attacks. The exposure of the full server path creates opportunities for attackers to understand the application's file structure, potentially leading to directory traversal attacks, local file inclusion vulnerabilities, or other path-based exploitation techniques. This vulnerability aligns with ATT&CK technique T1083 - File and Directory Discovery, as it enables adversaries to gather system information that would normally be restricted. The information disclosure can be leveraged by attackers to map the application's directory structure, identify potential weak points in the file system permissions, and understand how the application interacts with the underlying operating system.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and error handling mechanisms throughout the WebLinks module. The most effective approach involves sanitizing all user inputs by validating parameter values against expected formats and implementing custom error handling that prevents the display of system paths in error messages. Organizations should configure PHP to disable error display in production environments and instead log errors to secure files without exposing sensitive information to end users. The implementation of proper access controls and input validation should follow the principle of least privilege, ensuring that all parameters are validated before processing and that error messages do not contain system-specific information. Additionally, regular security audits and code reviews should be conducted to identify similar input validation gaps in other modules, as this vulnerability demonstrates the importance of comprehensive security testing across all application components.