[KAPDA::#25] - MyBB 1.x Cross_Site_Scripting

KAPDA New advisory

Vulnerable products : MYBB 1.x
Vendor:  www.mybboard.net/
Risk: medium 
Vulnerabilities: Cross_Site_Scripting
Discoverd by Roozbeh Afrasiabi
www.persiax.com

Date :
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Found : Jan 21 2006
Vendor Contacted : N/A
Release Date : N/A

About :
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MyBB is a powerful, efficient and free forum package developed in PHP and MySQL.MyBB has been designed with the end users in mind, you and your subscribers. Full control over your discussion  system is p resented right  at the tip  of your  fingers, from multiple  styles and  themes to the ultimate  customisation of your forums using the template system.



Vulnerability:
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Cross_Site_Scripting (XSS,CSS):

MYBB is affected by a  cross-site scripting  vulnerability. This issue is due to the failure of the application to properly sanitize user-supplied input.

As a result of this vulnerability, it is possible for a remote attacker to create a malicious link containing script code that will be executed  in the browser of an unsuspecting user when followed. 


Detail and PoC :
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1)

The application does not validate the "notepad" variable upon submission to the usercp.php script via the POST method.The personal pad would save this data which would later be displayed to the user(i.e on visiting the persoanal pad page).  

h**p://[target]/usercp.php?action=notepad
notepad=</textarea><script>alert(document.cookie)</script>


2)

This flaw exists because the application does not validate the "signature" variable upon submission to the usercp.php script via the POST method.

h**p://[target]/usercp.php?action=editsig
signature=</textarea><script>alert(document.cookie)</script>



Solution :
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N/A


Original Advisory :
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http://kapda.ir/advisory-241.html


Credit :
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Discoverd by Roozbeh Afrasiabi
roozbeh_afrasiabi[at]yahoo.com
black_death[at]kapda.ir
www.persiax.com