{keyword} Union All Select Null,null,null,null-- Uizf -

: The attacker is attempting to determine the number of columns returned by the original database query. By adding NULL values until the page loads without an error, they can identify the table's structure.

: In some cases, these injections can be used to log in without a valid password. {KEYWORD} UNION ALL SELECT NULL,NULL,NULL,NULL-- Uizf

: This command tells the database to combine the results of the original query with a new "injected" query. : The attacker is attempting to determine the

: Once the column count is known, they replace the NULL values with actual commands (e.g., version() , user() , or table_name ) to steal sensitive information. {KEYWORD} UNION ALL SELECT NULL,NULL,NULL,NULL-- Uizf