WarehousePG (WHPG) 6.27.1 through 6.27.6 and 7.2.1 through 7.6.0 are affected by a missing authorization vulnerability (CWE-862) in the built-in cluster expansion functions gp_expand_lock_catalog() and gp_expand_bump_version(). Any authenticated database role can run them, and neither checks privileges. A low-privileged user can call gp_expand_lock_catalog() inside an open transaction to block all catalog changes across the cluster for every user, superusers included, until that transaction ends, which in practice requires a superuser to terminate the session. Blocked changes include DDL, temporary table creation, GRANT and CREATE ROLE. The same user can call gp_expand_bump_version() repeatedly. Each call disconnects sessions that hold temporary tables, with a FATAL error on their next catalog change, and makes every other session rebuild its segment connections.
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.