Ajax File and Image Manager v1.0 Final Remote Code Execution Vulnerability

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Ajax File and Image Manager v1.0 Final Remote Code Execution Vulnerability
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author...........: Egidio Romano aka EgiX
mail.............: n0b0d13s[at]gmail[dot]com
software link....: http://www.phpletter.com/

[-] Vulnerability explanation:

The vulnerable code is located into /ajaxfilemanager/ajax_create_folder.php:

11. @ob_start();
12. displayArray($_POST);
13. writeInfo(@ob_get_clean());

this script start the output buffering at line 11 and then call the 'displayArray'
function that simply displays the $_POST array content with the print_r() function,
and finally at line 13 is called the 'writeInfo' function using the current buffer
contents as parameter (that is the $_POST array content). Now look at the 'writeInfo'
function body defined into /ajaxfilemanager/inc/function.base.php:

228. function writeInfo($data, $die = false)
229. {
230.   $fp = @fopen(dirname(__FILE__) . DIRECTORY_SEPARATOR . 'data.php', 'w+');
231.   @fwrite($fp, $data);
232.   @fwrite($fp, "\n\n" . date('d/M/Y H:i:s') );
233.   @fclose($fp);

It writes the $data paramater into a file called 'data.php' without any check,
so an attacker could be able to inject and execute arbitrary PHP code.

[-] Disclosure timeline:

[21/10/2011] - Vulnerability discovered
[24/10/2011] - Issue reported via e-mail
[25/10/2011] - Vendor replied that a fix will be released in the next version
[04/11/2011] - Public disclosure