UAA can issue tokens across identity providers if users with matching usernames exist

Vulnerability Description

Cloud Foundry UAA, versions 60 prior to 66.0, contain an authorization logic error. In environments with multiple identity providers that contain accounts across identity providers with the same username, a remote authenticated user with access to one of these accounts may be able to obtain a token for an account of the same username in the other identity provider.

References

• http://www.securityfocus.com/bid/106240
• https://www.cloudfoundry.org/blog/cve-2018-15754/
• https://www.cloudfoundry.org/blog/cve-2018-15754