: This is a SQL comment. It tells the database to ignore everything that follows it (like the original developer's remaining code), which prevents the rest of the legitimate query from causing a syntax error.
: The attacker uses NULL values to figure out how many columns are in the original database table. If the number of NULL s doesn't match the number of columns in the original query, the database will return an error.
The string you provided is a . Specifically, it is designed to exploit a vulnerability in a database-driven application to extract unauthorized data. : This is a SQL comment
: This part attempts to "break out" of a standard SQL query. It uses a closing quote and parenthesis to terminate whatever the original developer intended the query to do.
Are you seeing this in your , or are you testing the security of your own code ? If the number of NULL s doesn't match
: Ensure all data entered by users is cleaned and validated before it hits your database.
: A WAF can often block these types of patterned attacks automatically. : This part attempts to "break out" of a standard SQL query
If you found this in your website's logs, it means someone (or an automated bot) was . It is a common sign of a "SQLi" attack. To protect your application, you should: