The best recommendation by the IS auditor for finding that application servers had inconsistent security settings leading to potential vulnerabilities is to perform a configuration review. A configuration review is an audit procedure that involves examining and verifying the security settings and parameters of application servers against predefined standards or best practices. A configuration review can help to identify and remediate any deviations, inconsistencies, or misconfigurations thatmay expose the application servers to unauthorized access, exploitation, or compromise6. A configuration review can also help to ensure compliance with security policies and regulations, as well as enhance the performance and availability of application servers. The other options are less effective or incorrect because:

A. Improving the change management process is not the best recommendation by the IS auditor for finding that application servers had inconsistent security settings leading to potential vulnerabilities, as it does not address the root cause of the problem or provide a specific solution. While improving the change management process may help to prevent future inconsistencies or misconfigurations in application server settings, it does not ensure that the existing ones are detected and corrected.

B. Establishing security metrics is not the best recommendation by the IS auditor for finding that application servers had inconsistent security settings leading to potential vulnerabilities, as it does not address the root cause of the problem or provide a specific solution. While establishing security metrics may help to measure and monitor the security performance and posture of application servers, it does not ensure that the existing inconsistencies or misconfigurations in application server settings are detected and corrected.

C. Performing a penetration test is not the best recommendation by the IS auditor for finding that application servers had inconsistent security settings leading to potential vulnerabilities, as it does not address the root cause of the problem or provide a specific solution. While performing a penetration test may help to simulate and evaluate the impact of an attack on application servers, it does not ensure that the existing inconsistencies or misconfigurations in application server settings are detected and corrected. References: Configuring system to useapplication server security - IBM, Application Security Risk: Assessment and Modeling - ISACA, Five Key Components of an Application SecurityProgram - ISACA, ISACA Practitioner Guidelines for Auditors - SSH, SCADA Cybersecurity Framework - ISACA