This specific string is designed to be appended to a vulnerable input field (the {KEYWORD} in your example) to probe the database structure: : Closes the original string literal in the SQL query.
: This is a SQL comment, which tells the database to ignore the rest of the original, legitimate query that follows. The Goal of the Attack This specific string is designed to be appended
If the column count is wrong (e.g., the original query has 7 or 9 columns), the database will return an error. NULL is used because it is compatible with
NULL is used because it is compatible with almost any data type (string, integer, date, etc.), ensuring the query won't fail due to data type mismatches. What this Payload Does
: Appends a new set of results to the original query's output.
The payload you provided, ' UNION ALL SELECT NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL-- , is a common pattern used in to determine the number of columns returned by an original database query. What this Payload Does