What is the BEST mitigation strategy to prevent an attack detected in web logs?

Input validation is considered the best mitigation strategy to prevent attacks detected in web logs because it involves checking and sanitizing user inputs before they are processed by the application. Many web-based attacks, such as SQL injection, cross-site scripting (XSS), and command injection, exploit weaknesses in how input is handled. By ensuring that only valid data is processed, applications can effectively defend against these types of attacks.

Strong input validation will enforce rules on what constitutes acceptable input, such as restricting data types, lengths, and formats. This preemptively blocks malicious content from being executed within the system, thereby reducing the chance of successful attacks reflected in web logs.

While other options like securing cookies, code signing, and utilizing stored procedures play roles in overall application security, they do not directly address the core issue of checking and validating user input, which is essential for mitigating many common web application attacks.