CVE-2024-22018 in Node.js
Summary
by MITRE • 07/10/2024
A vulnerability has been identified in Node.js, affecting users of the experimental permission model when the --allow-fs-read flag is used. This flaw arises from an inadequate permission model that fails to restrict file stats through the fs.lstat API. As a result, malicious actors can retrieve stats from files that they do not have explicit read access to. This vulnerability affects all users using the experimental permission model in Node.js 20 and Node.js 21. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.
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Analysis
by VulDB Data Team • 11/01/2024
The vulnerability described in CVE-2024-22018 represents a critical flaw in Node.js's experimental permission model that undermines fundamental security boundaries. This issue specifically impacts users who have enabled the experimental permission system and are utilizing the --allow-fs-read flag, creating a dangerous privilege escalation vector. The flaw stems from insufficient access control implementation within the file system API, where the fs.lstat function fails to properly enforce permission restrictions that should prevent unauthorized file metadata access. This represents a direct violation of the principle of least privilege and demonstrates a fundamental weakness in the permission model's design. The vulnerability affects Node.js versions 20 and 21, which are currently in active development and usage phases, making this issue particularly concerning for organizations relying on these versions.
The technical implementation of this vulnerability involves the fs.lstat API function failing to properly validate access permissions before returning file statistics information. When a user employs the --allow-fs-read flag, the system should restrict file access to only those files explicitly granted read permissions, but the current implementation allows retrieval of file metadata from restricted files through the lstat function. This creates a scenario where attackers can enumerate file system structure and gather information about files they should not have access to, potentially enabling further attacks such as file enumeration, directory traversal, or information disclosure. The vulnerability operates at the system call level where file system metadata is accessed without proper authorization checks, making it particularly dangerous for applications that rely on the permission model for security isolation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable more sophisticated attack vectors within compromised Node.js applications. Attackers can leverage this weakness to map file system structures, identify sensitive files, and potentially discover other vulnerabilities in the application's file handling logic. This type of information leakage can facilitate subsequent attacks such as path traversal, file inclusion, or privilege escalation attempts that rely on understanding the underlying file system layout. The vulnerability particularly affects applications that implement security through the experimental permission model, which may be used in serverless environments, containerized applications, or any Node.js deployment where strict file access controls are expected. Organizations using Node.js 20 and 21 with experimental permissions enabled face significant risk of unauthorized file metadata access, which could lead to comprehensive system reconnaissance and targeted attacks.
Organizations should immediately disable the experimental permission model in affected Node.js versions until a patched release is available, as this vulnerability cannot be adequately mitigated through configuration changes alone. The recommended approach involves either upgrading to a patched version of Node.js or completely disabling the --allow-fs-read flag and experimental permission model functionality. Security teams should implement monitoring for unauthorized file system access patterns and conduct thorough audits of applications that rely on experimental Node.js features. The vulnerability aligns with CWE-284 (Improper Access Control) and represents a specific implementation weakness in the Node.js permission subsystem that violates standard security practices. From an ATT&CK framework perspective, this vulnerability enables information gathering techniques and privilege escalation pathways, specifically mapping to T1083 (File and Directory Discovery) and T1565 (Data Manipulation) tactics. Organizations should also consider implementing additional application-level controls and file system monitoring to detect potential exploitation attempts, as the experimental nature of the permission model means that other similar vulnerabilities may exist within the same codebase.