The string is a classic example of a SQL Injection (SQLi) payload, specifically used for database reconnaissance.
Ensure the database user account used by the web application has limited permissions.
The database ignores the final quote and semicolon, executes the sort, and confirms to the attacker that the query is valid and contains at least one column. 4. Impact
Attackers increment this number (e.g., ORDER BY 2 , ORDER BY 3 ). When the database throws an error (e.g., "The ORDER BY position number 10 is out of range"), the attacker knows exactly how many columns the original query is fetching.