: Rejecting any input that contains SQL keywords like UNION , SELECT , or comments ( -- ).
: The attacker is attempting to determine the number of columns being returned by the original query. They add NULL values until the database stops returning an error, which reveals the table's structure. : Rejecting any input that contains SQL keywords
: This is a SQL comment symbol. It tells the database to ignore everything that follows it, effectively neutralizing the rest of the original, legitimate code. : This is a SQL comment symbol
: This is likely a "fingerprint" or a unique string used by automated scanning tools (like SQLmap) to identify if the injected code was successfully processed. The "Essay" of a Vulnerability The "Essay" of a Vulnerability : By injecting
: By injecting ten NULL values, the attacker is essentially asking the database, "Do you have ten columns?" If the page loads normally, the answer is "yes."
If we were to view this string as a narrative, it tells the story of a .
: This command is used to combine the results of two different SQL queries. Attackers use it to append their own data to the output of a legitimate query.