CVE-2014-6394 in Xcode
Summary
by MITRE
visionmedia send before 0.8.4 for Node.js uses a partial comparison for verifying whether a directory is within the document root, which allows remote attackers to access restricted directories, as demonstrated using "public-restricted" under a "public" directory.
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Analysis
by VulDB Data Team • 06/16/2022
The vulnerability identified as CVE-2014-6394 affects the visionmedia send middleware for Node.js versions prior to 0.8.4, representing a critical directory traversal flaw that undermines web application security. This vulnerability stems from an improper implementation of directory validation logic within the middleware's file serving functionality, creating a pathway for malicious actors to bypass intended access controls and gain unauthorized access to restricted directories.
The technical flaw manifests through a partial string comparison mechanism that fails to properly validate whether requested file paths remain within the designated document root directory. When an application uses the send middleware to serve static files, the vulnerability allows attackers to manipulate file paths using directory traversal sequences such as "../" to navigate outside the intended document root. The specific demonstration involves accessing files in a "restricted" subdirectory when the middleware is configured with a "public" document root, exploiting the incomplete validation logic that does not fully resolve and compare absolute paths before granting access.
This vulnerability directly impacts the security model of Node.js web applications by potentially exposing sensitive files, configuration data, and system resources that should remain protected. Attackers can leverage this flaw to access files outside the intended serving directory, potentially obtaining database credentials, application source code, configuration files, or other sensitive information stored in restricted locations. The operational impact extends beyond simple data exposure to include potential system compromise through access to application internals and configuration details that could inform further attacks.
The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and represents a classic example of path traversal attacks that have been consistently exploited in web application security. From an attack framework perspective, this vulnerability maps to the privilege escalation and reconnaissance phases of the ATT&CK methodology, allowing threat actors to move laterally within compromised systems and gather intelligence for more sophisticated attacks. Organizations using vulnerable versions of the visionmedia send middleware should immediately implement patch updates to version 0.8.4 or later, while also reviewing their file serving configurations to ensure proper path validation and access controls are in place.
Mitigation strategies should include immediate patching of affected systems, implementation of proper path normalization and validation checks, and comprehensive security testing of file serving components. Additional protective measures include restricting file permissions, implementing proper input sanitization, and deploying web application firewalls to detect and block suspicious path traversal attempts. Organizations should also conduct thorough security audits of their Node.js applications to identify other potential path traversal vulnerabilities in similar middleware components and ensure that all file serving functionality properly validates and restricts access to system resources.