Kargo manages and automates the promotion of software artifacts. From 1.7.0 to before v1.7.8, v1.8.11, and v1.9.3, the batch resource creation endpoints of both Kargos legacy gRPC API and newer REST API accept multi-document YAML payloads. Specially crafted payloads can manifest a bug present in the logic of both endpoints to inject arbitrary resources (of specific types only) into the underlying namespace of an existing Project using the API servers own permissions when that behavior was not intended. Critically, an attacker may exploit this as a vector for elevating their own permissions, which can then be leveraged to achieve remote code execution or secret exfiltration. Exfiltrated artifact repository credentials can be leveraged, in turn, to execute further attacks. In some configurations of the Kargo control planes underlying Kubernetes cluster, elevated permissions may additionally be leveraged to achieve remote code execution or secret exfiltration using kubectl. This can reduce the complexity of the attack, however, worst case scenarios remain entirely achievable even without this. This vulnerability is fixed in v1.7.8, v1.8.11, and v1.9.3.
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.