CVE-2024-21896: 
npm vulnerability analysis and mitigation

The vulnerability (CVE-2024-21896) affects Node.js versions 20.x and 21.x, specifically targeting the experimental permission model. Discovered and disclosed in February 2024, this high-severity vulnerability allows path traversal attacks through manipulation of Buffer internals (NodeJS Blog, NVD).

The vulnerability exists in the permission model's path traversal protection mechanism. When the permission model processes paths that need to be treated as a Buffer, it calls path.resolve() and then uses Buffer.from() to obtain a Buffer from the result. However, by monkey-patching Buffer internals, specifically Buffer.prototype.utf8Write, an attacker can modify the result of path.resolve(), leading to a path traversal vulnerability. The vulnerability has received a CVSS v3.0 base score of 7.9 (High) with vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N (NVD).

Successful exploitation of this vulnerability could lead to disclosure of sensitive information, addition or modification of data, or Denial of Service (DoS). The vulnerability specifically affects the experimental permission model, which is a critical security feature in Node.js (NetApp Security).

The vulnerability has been patched in Node.js version 20.11.1 and subsequent releases. Users are strongly recommended to upgrade to these patched versions. Red Hat has also released security updates to address this vulnerability in their Enterprise Linux distributions (Red Hat Advisory).

Multiple vendors and organizations have responded to this vulnerability by issuing advisories and patches. NetApp has conducted comprehensive assessments of their products and provided detailed advisories. Red Hat has classified this as an 'Important' security update and has released patches for affected systems (NetApp Security, Red Hat Advisory).