Pimcore Customer Data Framework Improper Access Control allows unprivileged user to access customers duplicates list

Summary

An authenticated and unauthorized user can access the list of potential duplicate users and see their data.

Details

Permissions do not seem to be enforced when reaching the /admin/customermanagementframework/duplicates/list endpoint allowing an authenticated user without the permissions to access the endpoint and query the data available there. It seems that the access control is not enforced in this place : https://github.com/pimcore/customer-data-framework/blob/b4af625ef327c58d05ef7cdf145fa749d2d4195e/src/Controller/Admin/DuplicatesController.php#L43

PoC

In order to reproduce the issue, the following steps can be followed :

1. As an administrator : a. Create a role without any permission through Settings → User & Roles → Roles in the administration panel b. Create an user through Settings → User & Roles → Users and assign it the unprivileged role previously created
2. Log out the current administrator and log in with this new user
3. Access to the following endpoint https://pimcore_instance/admin/customermanagementframework/duplicates/list and the results will be returned to this unauthorized user

Impact

An unauthorized user can access PII data from customers without being authorized to.