CVE-2023-32003 is a security vulnerability identified in the Node.js runtime environment, specifically affecting the experimental permission model introduced in Node.js version 20 and earlier versions listed (4.0 through 20.0). The flaw exists in the implementation of the fs.mkdtemp() and fs.mkdtempSync() APIs, which are designed to create temporary directories with unique names. Due to a missing validation check, these functions can be exploited via a path traversal attack to bypass the permission model. This allows a malicious actor to create arbitrary directories outside of the intended sandbox or permitted file system scope. The vulnerability arises because the permission model, still experimental at the time of disclosure, does not adequately restrict directory creation paths when using these APIs. Although the vulnerability does not require authentication or user interaction, it targets users who have enabled the experimental permission model in Node.js, which may limit the affected population. There are no known exploits in the wild at the time of publication, and no official patches or mitigations have been linked yet. The absence of a CVSS score indicates the need for a severity assessment based on impact and exploitability factors. Overall, this vulnerability undermines the integrity and availability of the file system environment by allowing unauthorized directory creation, potentially facilitating further attacks such as privilege escalation or persistent footholds within affected systems running Node.js with the experimental permission model enabled.

For European organizations, the impact of CVE-2023-32003 depends largely on the adoption of Node.js 20 or earlier versions with the experimental permission model enabled. Organizations using Node.js in development or production environments that leverage this experimental feature could face unauthorized directory creation, leading to potential integrity violations and increased attack surface. This could facilitate further exploitation such as placing malicious files, evading security controls, or disrupting application behavior. Given Node.js's widespread use in web services, cloud applications, and internal tooling, especially in sectors like finance, telecommunications, and technology, the vulnerability could impact service reliability and data integrity. However, since the permission model is experimental, many organizations may not have it enabled, reducing immediate risk. The lack of known exploits suggests a low likelihood of active attacks currently, but the vulnerability could be leveraged in targeted attacks against high-value European entities, particularly those with complex Node.js deployments or custom permission configurations. The impact on confidentiality is limited unless combined with other vulnerabilities, but integrity and availability risks are moderate due to unauthorized directory creation capabilities.

1. Disable the experimental permission model in Node.js until an official patch or update addresses this vulnerability, especially in production environments. 2. Monitor Node.js releases closely for security updates that patch this vulnerability and apply them promptly. 3. Implement strict input validation and sandboxing at the application level to prevent path traversal and unauthorized file system access, regardless of Node.js permission model status. 4. Use containerization or virtualization to isolate Node.js applications, limiting the impact of any unauthorized directory creation. 5. Conduct code reviews and security audits focusing on file system operations, particularly those involving temporary directory creation. 6. Employ runtime monitoring tools to detect anomalous file system changes indicative of exploitation attempts. 7. Educate development teams about the risks of using experimental features in production and encourage adherence to stable, well-tested APIs. 8. If the experimental permission model is necessary, implement additional custom permission checks around fs.mkdtemp() usage to mitigate unauthorized directory creation.