CVE-2017-16124 in node-server-forfront
Summary
by MITRE
node-server-forfront is a simple static file server. node-server-forfront is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
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Analysis
by VulDB Data Team • 02/16/2020
The vulnerability identified as CVE-2017-16124 affects node-server-forfront, a lightweight static file server implementation written in node.js. This particular server software serves static content but fails to properly validate user-supplied input when processing file requests through the web interface. The flaw manifests as a directory traversal vulnerability that allows attackers to access arbitrary files on the server's filesystem by manipulating URL parameters with sequences of "../" directory navigation elements. This type of vulnerability represents a critical security weakness that can lead to unauthorized data access, system compromise, and potential information disclosure.
The technical root cause of this vulnerability stems from insufficient input validation and sanitization within the server's file path handling logic. When a user requests a file through the web interface, the application does not properly sanitize the requested path before attempting to serve the file. This allows an attacker to inject directory traversal sequences that can navigate beyond the intended document root directory. The vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The attack vector is straightforward and exploitable through simple URL manipulation, making it particularly dangerous as it requires minimal technical expertise to execute successfully.
The operational impact of this vulnerability extends beyond simple file access, as it can enable attackers to retrieve sensitive system files, configuration data, and potentially execute arbitrary code if the server is running with elevated privileges. Attackers could access critical system files such as password hashes, database connection strings, application configuration files, or even system binaries that could lead to further exploitation. The vulnerability affects any environment where node-server-forfront is deployed and accessible to untrusted users, including development environments, staging servers, and production systems. According to ATT&CK framework, this vulnerability aligns with T1083 (File and Directory Discovery) and T1566 (Phishing with Malicious Attachments) as attackers can use directory traversal to discover and exfiltrate sensitive information from compromised systems.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and sanitization measures. The most effective approach involves implementing strict path validation that prevents traversal sequences from being processed, including removing or encoding any "../" or similar directory navigation patterns from user input before processing file requests. Organizations should also consider implementing proper access controls and least privilege principles for the server process, ensuring that it runs with minimal required permissions. Additionally, network-level firewalls and web application firewalls should be configured to monitor and block suspicious URL patterns that attempt directory traversal attacks. The remediation process should include thorough code review to ensure all input handling mechanisms properly validate and sanitize user-supplied data, and regular security testing should be conducted to identify similar vulnerabilities in other components of the application stack. Organizations using this server software should also consider migrating to more robust and actively maintained static file serving solutions that have proper security controls built-in.