CVE-2023-32005 in Node.js
Summary
by MITRE • 09/12/2023
A vulnerability has been identified in Node.js version 20, affecting users of the experimental permission model when the --allow-fs-read flag is used with a non-* argument.
This flaw arises from an inadequate permission model that fails to restrict file stats through the `fs.statfs` 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.
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 • 02/14/2025
The vulnerability in Node.js version 20 represents a critical flaw within the experimental permission model implementation that fundamentally undermines the security boundaries designed to protect file system access. This issue specifically manifests when the --allow-fs-read flag is employed with non-wildcard arguments, creating an unexpected bypass mechanism that allows unauthorized access to file system metadata. The weakness stems from insufficient validation within the permission enforcement framework, where the system fails to properly restrict access to file system statistics through the fs.statfs API call. This represents a classic privilege escalation vulnerability that can be exploited by malicious actors to gather information about files they should not have access to, potentially enabling further attacks or reconnaissance activities.
The technical flaw operates at the intersection of file system abstraction and permission enforcement within Node.js's experimental security model. When users configure the --allow-fs-read flag with specific paths rather than wildcards, the permission system incorrectly permits access to file system statistics through fs.statfs calls while maintaining restrictions on actual file content access. This inconsistency creates a vector where attackers can enumerate file system metadata including file sizes, block counts, and other statistical information without having explicit read permissions for those files. The vulnerability is particularly concerning because it operates at the API level, allowing bypass of what should be strict access controls that separate file content access from file system metadata access.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attack vectors within compromised environments. Attackers who can leverage this flaw gain the ability to perform reconnaissance through file system enumeration, potentially mapping out directory structures and identifying sensitive files based on their statistical properties. This capability aligns with techniques described in the attack pattern taxonomy where adversaries use system information gathering to refine their targeting strategies. The vulnerability affects all users of Node.js 20 who utilize the experimental permission model, creating a broad attack surface that could impact applications ranging from web servers to command-line tools that rely on file system operations.
Security mitigations for this vulnerability should focus on immediate remediation through proper configuration of the experimental permission model or complete removal of the experimental feature until the underlying implementation is corrected. Organizations should avoid using specific path arguments with --allow-fs-read and instead rely on wildcard patterns or completely disable the experimental permission model in production environments. The issue directly relates to CWE-284 which addresses improper access control, and aligns with ATT&CK techniques involving privilege escalation and reconnaissance activities. Given that this is an experimental feature, the recommended approach includes disabling the permission model entirely and implementing proper access controls through application-level mechanisms rather than relying on potentially flawed system-level permissions. The vulnerability highlights the importance of thorough testing for experimental security features before deployment in production environments, as incomplete implementation can create dangerous security gaps that adversaries can exploit to gain unauthorized access to file system information.