The sequence you provided, "{KEYWORD} UNION ALL SELECT NULL-- KJAg" , is a classic example of a . Purpose of the Payload
: This is a random string (often called a "canary") used to identify the specific injection point in the application's output or logs. Context in "Content Production" {KEYWORD} UNION ALL SELECT NULL-- KJAg
: The UNION operator combines the results of two or more SELECT statements. By using SELECT NULL , a tester can determine how many columns the original database query expects without triggering a data-type error. The sequence you provided, "{KEYWORD} UNION ALL SELECT
: Someone is trying to see if they can extract sensitive data from your database. By using SELECT NULL , a tester can
: An automated scanner or a developer is checking if the input field is properly sanitized.
If you are seeing this in a content management system (CMS) or a search bar, it usually means:
: This is a SQL comment symbol. It tells the database to ignore the rest of the original query, effectively "breaking" the intended logic to execute the injected command instead.