vCluster Platform provides a Kubernetes platform for managing virtual clusters, multi-tenancy, and cluster sharing. Prior to versions 4.6.0, 4.5.4, 4.4.2, and 4.3.10, when an access key is created with a limited scope, the scope can be bypassed to access resources outside of it. However, the user still cannot access resources beyond what is accessible to the owner of the access key. Versions 4.6.0, 4.5.4, 4.4.2, and 4.3.10 fix the vulnerability. Some other mitigations are available. Users can limit exposure by reviewing access keys which are scoped and ensuring any users with access to them have appropriate permissions set. Creating automation users with very limited permissions and using access keys for these automation users can be used as a temporary workaround where upgrading is not immediately possible but scoped access keys are needed.
Weakness
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.