• Security risk: High (CVSS: 7.7)
  • Vulnerability: AccessToken API (if exposed) allows anyone to create a Token


LoopBack provides a built-in User management / authentication and authorization solution. As part of this solution, a User must have an AccessToken to authenticate themselves against APIs requiring authentication / authorization for data access.

By default the AccessToken Model is not exposed over a REST API but this configuration can be changed by a user in model-config.json by changing the public property to true or removing it (defaults to true if missing). Unless this API is exposed, a user is not vulnerable.

If the AccessToken Model is exposed over a REST API, it is then possible for anyone to create an AccessToken for any User provided they know the userId and can hence get access to the other user’s data / access to their privileges (if the user happens to be an Admin for example).

Reported by

@zbarbutos via Gitter

Versions affected

loopback version 2.39.2 and below


Upgrade to loopback 2.40.0 or later if your repository is using an outdated loopback package.

Ensure that your application’s package.json has the following line:

"dependencies": {
   "loopback": "^2.40.0",

Then upgrade your project dependencies to use the latest version :

$ cd <app-root>
$ npm update
Tags: security