Bugtraq mailing list archives

Re: CoolForum v 0.5 beta shows content of PHP files


From: David Woods <security () solidhouse com>
Date: Tue, 15 Oct 2002 21:04:23 -0600

If the webserver is not chrooted or otherwise protected from escaping a directory all files on the system will be 
potentially readable by an attacker (providing the user the webserver runs as has read permissions)

i.e.
http://<Forum_URL>avatar.php?img=3D../../../../../etc/passwd

David Woods
Solidhouse
http://www.solidhouse.com

On Sat, 12 Oct 2002 15:29:48 +0200
scrap <webmaster () securiteinfo com> wrote:

CoolForum v 0.5 beta shows content of PHP files
The original document can be found at
http://www.securiteinfo.com/attaques/hacking/coolforum0_5.shtml


.oO  Overview Oo.
CoolForum v 0.5 beta shows PHP content files
Discovered on 2002, September, 16th
Vendor: http://www.coolforum.net

CoolForum v 0.5 is a PHP forum. This forum can show content of PHP files.


.oO  Details Oo.
This forum contains a file named "avatar.php". This file can show an
image stored in the "logos" directory. Here is the source file of avatar.php :

<? header('Pragma: no-cache');
if (ereg(".jpg",$img))
   header("Content-Type: image/jpeg");
else if (ereg(".gif",$img))
   header("Content-Type: image/gif");
header('Expires: 0');

$fichier=3D"logos/$img";

$fp=3Dfopen($fichier,"r");
$image=3Dfread($fp,filesize($fichier));
fclose($fp);

echo($image);
?>

What this file do ? It's simple : It takes the name of the file as argument,
read it fully, and send back the content to your browser.
The security flaw is that *any* file, in or *out* the logos directory can be
show, bypassing *any* protected directories...


.oO  Exploit Oo.
The exploit is really easy. The aim is to read the "connect.php" file in the
"secret" directory. "connect.php" contains the informations about the
database connection and "secret" directory is protected by a .htaccess file.
You can do the exploit with any browser by using this syntax :
http://<Forum_URL>avatar.php?img=3D../secret/connect.php
Of course, replace <Forum_URL> by the vulnerable server.
You will get a blank page. If you edit the source of this web page, you'll
get the jackpot...


.oO  Solution Oo.
The vendor has been informed and has solved the problem.
Download CoolForum 0.5.1 or newer at :
http://www.coolforum.net/index.php?p=dlcoolforum



.oO  Discovered by Oo.
Arnaud Jacques aka scrap
webmaster () securiteinfo com
http://www.securiteinfo.com




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