An issue was discovered in OpenStack Keystone before 15.0.1, and 16.0.0. Any user authenticated within a limited scope (trust/oauth/application credential) can create an EC2 credential with an escalated permission, such as obtaining admin while the user is on a limited viewer role.
The information has been provided by Kay
The original article can be found at:https://security.openstack.org/ossa/OSSA-2020-004.html
This potentially allows a malicious user to act as the admin on a project another user has the admin role on, which can effectively grant that user global admin privileges.
OpenStack Keystone before 15.0.1
OpenStack Keystone before 16.0.0