The initial '{KEYWORD}' AND ... attempts to break out of a single-quoted string literal within a vulnerable SQL query. :
: Use bind variables (e.g., ? or :1 ) so the input is treated as data, not executable code.
: Strict allow-listing of expected characters for the {KEYWORD} field.
The payload attempts to force the database to trigger an error message that contains specific data, which confirms the vulnerability and the database type. :
The attacker sees this error in the HTTP response. Because the error contains the 1 (the result of the subquery), the attacker knows the injection worked. :
The payload injects a subquery: (SELECT (CASE WHEN (6957=6957) THEN 1 ELSE 0 END) FROM DUAL) . This is a "Boolean test" to see if the logic holds true. :
This string is a classic example of an payload, specifically targeting Oracle databases. Technical Breakdown