1. The most appropriate type of CAATs tool for testing security configuration settings for the entire application system would be a vulnerability scanner. This type of tool can automatically identify and report on security vulnerabilities, such as weak passwords, open ports, and outdated software versions, that could be exploited by attackers. It can also provide recommendations for remediation and help prioritize which vulnerabilities should be addressed first.

2. Here are four examples of computer-assisted auditing techniques (CAATs) with ACL (Audit Command Language) on a client web application:

Cash Disbursements: The auditor could use ACL to analyze the cash disbursements data to identify any unusual transactions or trends. For example, the auditor could use ACL to extract and sort data on large cash disbursements, check signatures, and other key fields to look for any anomalies.

Accounts Receivable: The auditor could use ACL to perform substantive tests on the accounts receivable data. This could include extracting data on overdue accounts, identifying credits issued to customers, and performing a detailed aging analysis to identify any overdue accounts that may require additional follow-up.

Payroll: The auditor could use ACL to analyze the payroll data to identify any potential fraud or errors. For example, the auditor could extract and review data on payroll transactions, including employee names, pay rates, and deductions, to look for any discrepancies or unauthorized changes.

Inventory Management: The auditor could use ACL to perform an inventory analysis to ensure that the client's inventory management processes are effective. This could include extracting data on inventory levels, performing a physical count reconciliation, and identifying any discrepancies between the physical count and inventory records. The auditor could also analyze the inventory turnover rate to ensure that inventory is being managed effectively.