Is it illegal for the property customer service staff to call the intermediary with the consent of the owner?

Illegal. Suspected of illegally leaking or obtaining citizens' personal information and infringing on the rights and interests of others. Legal basis: Article 120 of the Civil Law of People's Republic of China (PRC) infringes, and the infringed has the right to request the infringer to bear the tort liability. The owner's information is protected and cannot be disclosed.