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Advisory by Eye On Security Research Group - India www.eos-india.net

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1...............................................................Product

2................................................................Vendor

3.........................................................Vulnerability

4.........................................................About Product

5..............................................Details of vulnerability

6...............................................................Exploit

7..............................................................Solution

8...............................................................Credits

1. Product

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miniBB 1.7 (latest) and earlier

2. Vendor

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www.minibb.net

3. Vulnerability

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Cross Site Scripting vulnerability in bb_func_usernfo.php

4. About miniBB

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(direct quote from www.minibb.net)

miniBB ("minimalistic bulletin board") is flat linear (non-tree) version of highly customizable bulletin board. It inherits most popular features from the bulletin boards the planet has at this moment, with one exception: it is very small by size (2-5 times smaller than usual boards), very fast and FREE. Mostly miniBB is designed for small and medium Internet-sites, but also can be used in large projects.

5. Details of vulnerability

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bb_func_usernfo.php contains code to take data from "minibb_users" table and display information about a particular user requested. The code for displaying website of the any user in bb_func_usernfo.php is as follow :

if ($row[6]!='') $row[6]='<a href="'.$row[6].'" target="_blank">'.$row[6].'</a>'; else $row[6]='';

So an attacker can create a login in the forums and in the preferences, give his website name as http://blah.com"></a><script>somejavascriptcode</script>

Hence when others will try to view his profile, the inserted javascript code will be executed. The actual bug lies in the "bb_edit_prf.php" file where the website name inserted by a user in his preferences is not validated properly.

6. Exploit

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Create a user in the forums with your website name as

http://blah.com"></a><script>alert(document.cookie)</script>

Now suppose your userid is 5, then just clicking http://[target]/index.php?action=userinfo&user=5 will execute the script.

7. Solution

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Check for the validation of the user data while editing his preferences in the "bb_edit_prf.php" file and filter out strings like "<script>", quotes, "cookie" etc.

8. Credits

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Chintan Trivedi - http://www.hackersprogrammers.com

"Eye on Security Research Group - India " - www.eos-india.net

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