CVE-2019-3798: Escalation of Privileges in Cloud Controller

Severity

Medium

Vendor

Cloud Foundry Foundation

Affected Cloud Foundry Products and Versions

• CAPI-Release
  • All versions prior to 1.79.0

Description

Cloud Foundry Cloud Controller API Release, versions prior to 1.79.0, contains improper authentication when validating user permissions. A remote authenticated malicious user with the ability to create UAA clients and knowledge of the email of a victim in the foundation may escalate their privileges to that of the victim by creating a client with a name equal to the guid of their victim.

Detection

To tell if your system was exploited, run the following in the uaadb:

select client_id, oauth_client_details.authorities from oauth_client_details join users on oauth_client_details.client_id = users.id;

If results are returned with authorities including cloud_controller.read or cloud_controller.write the vulnerability was likely exploited.

Mitigation

UAA admins should be wary of requests to create clients with guid-shaped client_ids and cloud_controller authorities.

Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

• CAPI
  • Upgrade All versions to 1.79.0 or greater

History

2019-04-11: Initial vulnerability report published.