Union All Select Null,null,null,null,null,null,null,null,null-- Vitq: {keyword}'

: Fills columns with NULL values to match the column count of the original query, which is required for UNION to work. The attacker keeps adding NULL s until the error disappears (often 500 internal server error) and a '200 OK' response is received.

This SQL injection payload ( ' UNION ALL SELECT NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL-- vITQ ) is a classic technique used in to determine the exact number of columns returned by a vulnerable web application's original database query. Payload Breakdown ' : Closes the original SQL statement's string parameter. : Fills columns with NULL values to match

: A random string identifier often used in automated attacks to verify if the injected query is successfully displayed in the application response. Purpose and Workflow SQL injection UNION attacks | Web Security Academy Payload Breakdown ' : Closes the original SQL

: Combines the results of the original query with a new, malicious query. (or sometimes -- ): A comment marker that

(or sometimes -- ): A comment marker that hides the rest of the original SQL query, preventing syntax errors.