The primary objective of using this payload is . For a UNION operation to work, the injected query must have the exact same number of columns as the original query.
If the column count is wrong (e.g., the original query has 7 or 9 columns), the database will return an error. The primary objective of using this payload is
If the original query has 8 columns, the page will likely load normally or show an extra row of empty data. If the original query has 8 columns, the
: 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 What this Payload Does : Attempts to select
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
: Attempts to select 8 columns of "null" data.