: 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.
: The attacker finds an input field—perhaps a search bar or a login box—that isn't properly "sanitized" (cleaned of special characters). : The attacker is attempting to determine the
: 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." : By injecting ten NULL values, the attacker
: Once the column count is known, the attacker replaces the NULL s with commands to extract sensitive data, such as usernames, passwords, or credit card numbers. Prevention and Best Practices : Rejecting any input that contains SQL keywords
If we were to view this string as a narrative, it tells the story of a .
: These tools can automatically detect and block common SQLi patterns like the one you provided.
: Rejecting any input that contains SQL keywords like UNION , SELECT , or comments ( -- ).
