Which security measure should be prioritized to defend against SQL injection?

Prioritizing input validation on databases is essential in defending against SQL injection attacks. SQL injection occurs when an attacker can manipulate SQL queries by injecting malicious input into a web application's input fields. If the application does not validate or sanitize this input, it could lead to unauthorized data access, data manipulation, or even a complete compromise of the database system.

By implementing input validation, you ensure that only expected and safe data formats are accepted by the application. This involves checking user input against predefined rules, such as acceptable lengths, types, and characters. Properly sanitizing input helps to strip out or neutralize harmful SQL code, effectively preventing attackers from executing malicious queries.

While user awareness training is important for overall security practices, it does not directly prevent SQL injection vulnerabilities from occurring in the code. Installing antivirus software is useful for detecting and mitigating various types of malware but does not address the specific vulnerabilities present in SQL queries. Physical security of server rooms is vital for protecting hardware from unauthorized access but does not address the prevention of SQL injection on the application level. Thus, focusing on input validation is the most effective approach to guard against this specific type of attack.