Versions of the npm CLI prior to 6.13.3 are vulnerable to a symlink reference outside of node_modules. It is possible for packages to create symlinks to files outside of the
node_modules folder through the
bin field upon installation. A properly constructed entry in the package.json bin field would allow a package publisher to create a symlink pointing to arbitrary files on a user’s system when the package is installed. Only files accessible by the user running the
npm install are affected.
This behavior is still possible through install scripts. This vulnerability bypasses a user using the --ignore-scripts install option.
Upgrade to version 6.13.3 or later.