Apache NiFi 1.1.0 through 2.7.2 are missing authorization when updating configuration properties on extension components that have specific Required Permissions based on the Restricted annotation. The Restricted annotation indicates additional privileges required to add the annotated component to the flow configuration, but framework authorization did not check restricted status when updating a component previously added. The missing authorization requires a more privileged user to add a restricted component to the flow configuration, but permits a less privileged user to make property configuration changes. Apache NiFi installations that do not implement different levels of authorization for Restricted components are not subject to this vulnerability because the framework enforces write permissions as the security boundary. Upgrading to Apache NiFi 2.8.0 is the recommended mitigation.
Weakness
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
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.