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CVE-2014-2021 - vBulletin 5.x/4.x - persistent XSS in AdminCP/ApiLog via
xmlrpc API (post-auth)

============================================================================
====================

 

Overview

- --------

 

    date    :  10/12/2014  

    cvss    :  4.6 (AV:N/AC:H/Au:S/C:P/I:P/A:P) base

    cwe     :  79 

    

    vendor  : vBulletin Solutions

    product : vBulletin 4

    versions affected :  latest 4.x and 5.x (to date); verified <= 4.2.2  ;
<= 5.0.x

            * vBulletin 5.0.5      (verified)

           * vBulletin 4.2.2     (verified)  

            * vBulletin 4.2.1     (verified)  

            * vBulletin 4.2.0 PL2 (verified)  

                

    exploitability :

            * remotely exploitable

            * requires authentication (apikey)

            * requires non-default features to be enabled (API interface,
API-Logging)

            * requires user interaction to trigger exploit (admincp - admin
views logs)

                

    patch availability (to date) :  None

 

 

Abstract

- ---------

    vBulletin 4/5 does not properly sanitize client provided xmlrpc
attributes (e.g. client name)

    allowing the remote xmlrpc client to inject code into the xmlrpc API
logging page. 

    Code is executed once an admin visits the API log page and clicks on the
API clients name.

    

    risk:  rather low - due to the fact that you the api key is required

           you can probably use CVE-2014-2023 to obtain the api key

 

 

Details

- --------

    

    vulnerable component: 

        ./admincp/apilog.php?do=viewclient

    apilog.php does not sanitize xmlrpc client provided data before passing
it to

    print_label_row to generate the output page.

 

 

Proof of Concept (PoC)

- ----------------------

 

    see https://github.com/tintinweb/pub/tree/master/pocs/cve-2014-2021

    

    

    1) prerequesites

    1.1) enable API, generate API-key

         logon to AdminCP

         goto "vBulletin API"->"API-Key" and enable the API interface,
generate key

         goto "vBulletin API"->"API-Log" and enable all API logging

    2) run PoC

         edit PoC to match your TARGET, APIKEY (, optionally DEBUGLEVEL)

         run PoC, wait for SUCCESS! message

    3) trigger exploit

        logon to AdminCP

         goto "vBulletin API"->"API-Log" and hit "view"

         in search results click on "client name"

         the injected msgbox pops up

         

 

Timeline

- --------

 

    2014-01-14: initial vendor contact - no reply

    2014-01-24: vendor contact - no reply

    2014-10-13: public disclosure

    

Contact

- --------

 

    tintinweb - https://github.com/tintinweb/pub/cve-2013-2021

    

    

(0x721427D8)

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