CVE-2024-21896: nodejs node Path Traversal: 'dir/../../filename'

Vulnerability summary

CVE-2024-21896 is a critical (CVSS 9.8) Path Traversal: 'dir/../../filename' vulnerability in nodejs node. EPSS estimates a 1.26% chance of exploitation in the next 30 days, higher than 69.6% of scored vulnerabilities.

Timeline

1. 20-02-2024
   PublishedVulnerability first disclosed.
2. 30-04-2025
   Last modifiedVulnerability information updated.

Description

The permission model protects itself against path traversal attacks by calling path.resolve() on any paths given by the user. If the path is to be treated as a Buffer, the implementation uses Buffer.from() to obtain a Buffer from the result of path.resolve(). By monkey-patching Buffer internals, namely, Buffer.prototype.utf8Write, the application can modify the result of path.resolve(), which leads to a path traversal vulnerability. 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.

• CWE-27Path Traversal: 'dir/../../filename'The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize multiple internal "../" sequences that can resolve to a location that is outside of that directory.