A systems administrator configures a new application. The next day, a security analyst reviews the logs and identifies multiple accounts that had been created overnight with administrative privileges and connections from different countries. Which of the following solutions would have prevented this incident?

Input validation is a technique used to ensure that data entered into a system meets specific criteria, preventing attacks such as SQL injection or cross-site scripting. However, while it enhances security against data manipulation, it does not directly address issues related to unauthorized account creation or the misuse of administrative privileges.

A honeynet is a network set up to attract and trap potential attackers to study their methods or distract them from real targets. While it can enhance security awareness and threat detection, it does not prevent unauthorized account creation; thus, it would not address the immediate issue of multiple accounts being created with administrative privileges.

A Web Application Firewall (WAF) protects web applications by filtering and monitoring HTTP traffic. While it can defend against certain types of attacks, it does not specifically prevent unauthorized account creation or address the issue of administrative privilege misuse, making it less applicable in this scenario.