: A website takes user input and places it directly into a SQL query without "cleaning" it first.
If the page returns an error (like "The used SELECT statements have a different number of columns"), the attacker will try again with five or seven NULL values until the error disappears. 4. -- (The Comment) In SQL, double-dashes signify the start of a comment.
: NULL is used because it is compatible with almost any data type (integers, strings, dates, etc.). : A website takes user input and places
This is likely a or "signature" used by an automated vulnerability scanner (such as Burp Suite, SQLmap, or Acunetix).
This is the "probe" part of the injection. The attacker is trying to determine the number of columns being returned by the original database query. -- (The Comment) In SQL, double-dashes signify the
This is a SQL operator used to combine the result sets of two or more SELECT statements into a single result set.
This string is a classic example of a used by security researchers and attackers to probe a website's database for vulnerabilities. This is the "probe" part of the injection
: Any code that was supposed to follow the input (like a closing quote or a WHERE clause) is ignored by the database, preventing syntax errors that would break the injection. 5. GoJB