A SQL injection vulnerability allows an attacker to inject malicious SQL code into the application, potentially allowing them to access or modify sensitive data.
To prevent SQL injection attacks, do not trust client-side input and perform server-side validation. Use parameterized queries or prepared statements with placeholders for user input. Avoid concatenating strings into queries and never store plaintext passwords. Use stored procedures if possible. Implement a ‘least privilege’ approach by granting the minimum database access required for the application.