Database System Security Assessment

B.

The most important control for the auditor to confirm is the service port used by the database server has been changed.

Explanation: The migration of a database system containing personal and financial data for a bank's customers is a critical event that requires careful attention to security controls. The auditor's primary objective in assessing the security of the database system is to ensure that appropriate measures are in place to protect the confidentiality, integrity, and availability of the data.

Option A: The default configurations have been changed. Although changing default configurations is a good practice, it is not the most critical control in this scenario.

Option B: All tables in the database are normalized. Although normalization is a good practice to ensure data consistency and eliminate redundancy, it is not a security control.

Option C: The service port used by the database server has been changed. This is a critical security control as changing the default service port can help prevent unauthorized access to the database system. If the service port is not changed, attackers can use tools to scan the network for open ports and attempt to exploit vulnerabilities in the database system.

Option D: The default administration account is used after changing the account password. Although changing the default administration account password is a good practice, it is not the most critical control in this scenario. Additionally, using the default administration account is not recommended as attackers may already know the username and try to guess the password.

In summary, while all the controls listed may be important, the most important control for the auditor to confirm in this scenario is that the service port used by the database server has been changed.