What vulnerability does SQL injection exploit?

SQL injection exploits the vulnerability associated with failure to validate user input. This type of attack occurs when an application allows users to submit input that is not properly sanitized or validated. As a result, malicious users can craft inputs that manipulate SQL queries sent to a database, allowing them to execute arbitrary SQL code.

When an application directly incorporates user input into SQL statements without appropriate filtering or validation, it can lead to unauthorized access to or manipulation of the database. Attackers can exploit this vulnerability to perform actions such as retrieving sensitive data, modifying records, or potentially compromising the entire database host.

Proper user input validation is critical in preventing these types of attacks, ensuring that all data entered into the system adheres to expected formats and values before it is processed. This preventive measure is an essential part of secure coding practices and helps to mitigate the risk of SQL injection vulnerabilities.