CVE-2018-3733 in crud-file-server
Summary
by MITRE
crud-file-server node module before 0.9.0 suffers from a Path Traversal vulnerability due to incorrect validation of url, which allows a malicious user to read content of any file with known path.
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Analysis
by VulDB Data Team • 03/17/2023
The CVE-2018-3733 vulnerability affects the crud-file-server node module version 0.9.0 and earlier, presenting a critical path traversal flaw that enables unauthorized file access. This vulnerability resides in the module's improper validation of URL parameters, creating a significant security risk for applications that rely on this component for file serving functionality. The flaw allows attackers to manipulate URL paths and access files outside the intended directory structure, potentially exposing sensitive system information, configuration files, or user data. The vulnerability is particularly dangerous because it operates at the application layer, where it can be exploited through standard web requests without requiring elevated privileges or specialized tools.
The technical implementation of this vulnerability stems from inadequate input sanitization within the crud-file-server module's URL parsing logic. When the module processes file requests, it fails to properly validate or sanitize the requested file paths, allowing malicious users to inject directory traversal sequences such as ../ or ..\ into the URL parameters. This improper validation creates a direct path traversal condition where attacker-controlled input directly influences the file system operations. The vulnerability is classified as CWE-22 Path Traversal, which represents a well-known weakness in software applications that permit access to files and directories stored on the file system through manipulation of input parameters. The flaw essentially bypasses the intended file access controls and allows arbitrary file reading from the server's file system.
The operational impact of CVE-2018-3733 extends beyond simple information disclosure, as it can lead to complete system compromise when combined with other vulnerabilities or when sensitive files are accessible through the affected module. Attackers can leverage this vulnerability to access system configuration files, database credentials, application source code, or user data stored on the server. The vulnerability affects any application using the affected node module, making it particularly dangerous in environments where multiple applications or services depend on this component. Security researchers have identified that this vulnerability aligns with ATT&CK technique T1083 File and Directory Discovery, as attackers can systematically explore the file system to identify valuable targets. The impact is amplified when the affected server has weak file permissions or when the application runs with elevated privileges, potentially allowing attackers to access system-critical files or even execute arbitrary code.
Mitigation strategies for CVE-2018-3733 focus primarily on updating to version 0.9.0 or later of the crud-file-server module, which includes proper input validation and path sanitization mechanisms. Organizations should conduct comprehensive vulnerability assessments to identify all applications using this module and ensure immediate patching. Additional defensive measures include implementing proper input validation at multiple layers, using whitelist-based file access controls, and restricting file serving capabilities to specific directories. Security teams should also consider implementing web application firewalls that can detect and block suspicious path traversal attempts, as well as monitoring for unusual file access patterns that may indicate exploitation attempts. The vulnerability highlights the importance of proper secure coding practices and input validation, particularly when handling user-supplied data in file system operations, aligning with security standards that emphasize the need for robust sanitization and validation of all external inputs.