What is the time based bliend sql injection

Time-based blind SQL injection is a type of SQL injection attack where the attacker injects a SQL query that includes a delay or sleep function in order to determine whether a particular input field is vulnerable to SQL injection.

The attack typically involves injecting a time delay function such as sleep() or benchmark() into the SQL query, along with a boolean condition that evaluates to true or false based on a comparison of the injected value with a known value. For example, the following SQL query contains a time-based blind SQL injection:

SELECT * FROM users WHERE username = 'admin' AND password = 'password' AND (SELECT IF(1=1, SLEEP(5), 0));

In this query, the SLEEP() function is used to introduce a delay of 5 seconds if the condition 1=1 is true. By injecting a value that causes this condition to be true or false, an attacker can determine whether the input field is vulnerable to SQL injection.

Time-based blind SQL injection can be more difficult to detect and prevent than other types of SQL injection attacks because it does not generate error messages or other obvious signs of a successful attack. To prevent time-based blind SQL injection, it is important to use parameterized queries and input validation to ensure that user input is properly sanitized and does not contain any malicious code.