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

If you're building an application, you should never let user input go directly into a database query. Instead, use these industry-standard defenses:

: This is a comment operator in SQL. It tells the database to ignore the rest of the original query, preventing errors from trailing code. How to Prevent This If you're building an application, you should never

: This attempts to combine the results of the original legitimate database query with a new query controlled by the attacker. How to Prevent This : This attempts to

Use "allow-lists" to ensure input matches the expected format (e.g., ensuring a ZIP code is only numbers). If the number of NULL s doesn't match

: The attacker uses NULL values to figure out exactly how many columns the original table has. If the number of NULL s doesn't match the original column count, the database usually throws an error.

The string you provided is a common technique used in . Specifically: