CVE-2023-39331 in Node.js
Summary
by MITRE • 10/25/2023
A previously disclosed vulnerability (CVE-2023-30584) was patched insufficiently in commit 205f1e6. The new path traversal vulnerability arises because the implementation does not protect itself against the application overwriting built-in utility functions with user-defined implementations. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/14/2025
This vulnerability represents a critical path traversal flaw that emerged from an inadequate patch for a previously disclosed issue. The root cause lies in the Node.js runtime's insufficient protection mechanisms against malicious function overwrites, specifically targeting built-in utility functions that are essential for secure file operations. The vulnerability exists in the experimental permission model implementation, which was designed to provide fine-grained access controls but suffered from incomplete security measures.
The technical flaw exploits the absence of proper safeguards when user code attempts to overwrite core Node.js utility functions. When an attacker can manipulate or replace built-in functions such as those used for file system operations, they can effectively bypass intended security boundaries. This occurs because the permission model fails to prevent user-defined implementations from replacing critical system functions that handle path resolution and file access. The vulnerability becomes particularly dangerous when combined with the experimental nature of the permission model, as developers may not fully understand the security implications of the incomplete implementation.
The operational impact of this vulnerability is significant as it allows attackers to perform unauthorized file system operations that should be restricted by the permission model. An attacker could potentially traverse directories beyond intended boundaries, access restricted files, or execute arbitrary code through manipulated function overwrites. The experimental status of the permission model means that many developers may be using it in production environments without proper security considerations, making this vulnerability particularly dangerous. This type of vulnerability directly maps to CWE-22 Path Traversal and CWE-707 Improper Neutralization of Input, as it involves manipulation of input that affects path resolution and system function behavior.
Mitigation strategies must address both the immediate security gap and the broader implementation issues within Node.js. Organizations should immediately disable or carefully audit the experimental permission model until a proper implementation is available. The recommended approach involves implementing additional safeguards such as function integrity checks, runtime monitoring for function overwrites, and strict validation of all system function replacements. Security teams should also consider implementing network-level restrictions and monitoring for suspicious file access patterns. The ATT&CK framework categorizes this vulnerability under T1059 Command and Scripting Interpreter and T1566 Phishing, as attackers may use this vulnerability to gain unauthorized access to system resources and potentially escalate privileges through file system manipulation.