CVE-2017-16877 in Next.js
Summary
by MITRE
ZEIT Next.js before 2.4.1 has directory traversal under the /_next and /static request namespace, allowing attackers to obtain sensitive information.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/11/2023
The vulnerability identified as CVE-2017-16877 affects ZEIT Next.js versions prior to 2.4.1 and represents a directory traversal flaw within the application's request handling mechanism. This security weakness specifically manifests under the /_next and /static request namespaces, which are fundamental components of Next.js applications designed to serve static assets and framework resources. The flaw allows attackers to manipulate request paths and access files that should remain protected within the application's directory structure, potentially exposing sensitive system information that could compromise the entire application environment.
The technical implementation of this vulnerability stems from insufficient input validation and path sanitization within the Next.js framework's routing system. When requests are made to the /_next or /static endpoints, the application fails to properly sanitize user-supplied path parameters, enabling attackers to craft malicious requests using directory traversal sequences such as ../ or ..\ that can navigate beyond the intended asset directories. This type of vulnerability directly maps to CWE-22, which classifies directory traversal attacks as a common weakness in application security where insufficient restrictions are placed on file system access paths. The flaw operates at the application layer, specifically within the static file serving mechanism that Next.js employs to deliver compiled assets to client browsers.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential pathways for attackers to access sensitive configuration files, source code, environment variables, and other critical system information that could be used for further exploitation. Attackers could potentially access server-side files containing database credentials, API keys, or other confidential data that should remain isolated from public access. This vulnerability particularly affects web applications built using Next.js that handle user input through the static asset serving endpoints, making it a significant concern for organizations deploying these applications in production environments where security is paramount.
Mitigation strategies for CVE-2017-16877 require immediate application of the patched Next.js version 2.4.1 or later, which implements proper path validation and sanitization mechanisms to prevent directory traversal attacks. Organizations should also implement comprehensive input validation at multiple layers of their application architecture, including web application firewalls and reverse proxies that can intercept and filter malicious path sequences before they reach the application server. The remediation process should include thorough security testing of all static asset serving endpoints to ensure that no similar vulnerabilities exist within custom application code that might expose similar attack vectors. Additionally, implementing proper access controls and least privilege principles for static asset directories can significantly reduce the potential impact of such vulnerabilities, aligning with security best practices outlined in the MITRE ATT&CK framework under the technique of privilege escalation and credential access.