December 2019 Security Releases

These releases update npm to v6.13.4 to address three vulnerabilities described below.

All current release lines were affected.

At this time, CVEs have been requested by npm, Inc. and are pending review. See https://twitter.com/ahmadnassri/status/1205132161961123841 for more information.

Global node_modules Binary Overwrite

Versions of the npm CLI prior to 6.13.4 are vulnerable to a Global node_modules Binary Overwrite. It fails to prevent existing globally-installed binaries to be overwritten by other package installations.

For example, if a package was installed globally and created a serve binary, any subsequent installs of packages that also create a serve binary would overwrite the first binary. This will not overwrite system binaries but only binaries put into the global node_modules directory.

This behavior is still allowed in local installations and also through install scripts. This vulnerability bypasses a user using the --ignore-scripts install option.

Symlink reference outside of node_modules

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.

Arbitrary File Write

Versions of the npm CLI prior to 6.13.3 are vulnerable to an Arbitrary File Write. It fails to prevent access to folders outside of the intended node_modules folder through the bin field. A properly constructed entry in the package.json bin field would allow a package publisher to create files on a user's system when the package is installed. It is only possible to affect files that the user running npm install has access to and it is not possible to overwrite files that already exist on disk.

This behavior is still possible through install scripts. This vulnerability bypasses a user using the --ignore-scripts install option.

Downloads

Please note that this will be the final release of the v8.x line as support ends after December 31st, 2019.

Summary

The Node.js project will release new versions of all supported release lines on or shortly after Tuesday December 17, 2019 UTC. For versions 8, 10, and 12 the only update to the runtime in these releases will be an updated version of npm addressing the vulnerability announced in https://blog.npmjs.org/post/189618601100/binary-planting-with-the-npm-cli. Version 13, while still being a security release, will include all commits that were scheduled to be included in the originally scheduled release.

In the meantime, users should update to npm 6.13.4 by following the instructions provided in the npm advisory. As a general rule, avoid running npm in production environments.

Impact

All versions of Node.js are vulnerable including the LTS and current releases: Node.js 8 (LTS "Carbon"), Node.js 10 (LTS "Dubnium") , Node.js 12 (LTS "Erbium"), and Node.js 13.

Release timing

Releases will be available at, or shortly after, Tuesday, December 17, 2019 UTC.

The current Node.js security policy can be found at https://nodejs.org/en/security/. Please follow the process outlined in https://github.com/nodejs/node/blob/master/SECURITY.md if you wish to report a vulnerability in Node.js.

Subscribe to the low-volume announcement-only nodejs-sec mailing list at https://groups.google.com/forum/#!forum/nodejs-sec to stay up to date on security vulnerabilities and security-related releases of Node.js and the projects maintained in the nodejs GitHub organization.