In lunary-ai/lunary before version 1.6.3, the application allows the creation of evaluators without enforcing a unique constraint on the combination of projectId and slug. This allows an attacker to overwrite existing data by submitting a POST request with the same slug as an existing evaluator. The lack of database constraints or application-layer validation to prevent duplicates exposes the application to data integrity issues. This vulnerability can result in corrupted data and potentially malicious actions, impairing the system's functionality.
The product requires that an actor should only be able to perform an action once, or to have only one unique action, but the product does not enforce or improperly enforces this restriction.