: Most modern frameworks like Hibernate or Entity Framework handle this protection automatically.

If this payload successfully returns a blank page instead of an error, it confirms to a tester that the application is vulnerable. From there, they can replace the NULL s with commands to extract sensitive data, such as: Usernames and passwords. Database version and configuration details. The entire contents of specific tables. How to Prevent It

: Only allow expected characters and formats.

: This is a common reconnaissance technique. An attacker uses NULL values to determine the exact number of columns returned by the original query. If the number of NULL s doesn't match the original column count, the database will usually throw an error. By adding or removing NULL s, an attacker can find the correct structure.

To protect your application from this type of attack, you should avoid building queries using simple string concatenation. Instead, use:

: This part attempts to "break out" of the existing SQL command. The closing parenthesis ) is used to close a function or a nested query that the developer originally intended.