Path Traversal: 'dir/../../filename'

Summary

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 versions 20.x prior to 20.11.1 and 21.x prior to 21.6.2. Please note that at the time this CVE was issued, the permission model is an experimental feature of Node.js.