Tuesday, February 22, 2011

Vanilla Forums 2.0.17.1 ~ 2.0.17.5 <= Cross Site Scripting Vulnerability



1. OVERVIEW

The Vanilla Forums 2.0.17.1 till 2.0.17.5  were vulnerable to Cross Site Scripting.


2. BACKGROUND

Vanilla Forums are open-source, standards-compliant, customizable discussion forums.
It is specially made to help small communities grow larger through SEO mojo, totally customizable social tools,
and great user experience. Vanilla is also built with integration at the forefront, so it can
seamlessly integrate with your existing website, blog, or custom-built application.


3. VULNERABILITY DESCRIPTION

The 'p' parameter  was not properly sanitized upon submission to the /index.php url, which allows attacker to conduct Cross Site Scripting attack.
This may allow an attacker to create a specially crafted URL that would execute arbitrary script code in a victim's browser.


4. VERSIONS AFFECTED

2.0.17.1 ~ 2.0.17.5


5. PROOF-OF-CONCEPT/EXPLOIT

http://localhost/vanilla/index.php?p=/entry/"><script>alert(/XSS/)</script>


6. SOLUTION

Upgrade to Vanilla Forums 2.0.17.6 or higher


7. VENDOR

Vanilla Forums Development Team
http://vanillaforums.org/


8. CREDIT

This vulnerability was discovered by Aung Khant, http://yehg.net, YGN Ethical Hacker Group, Myanmar.


9. DISCLOSURE TIME-LINE

2010-01-25: notified vendor
2011-01-27: vendor released fix
2011-02-22: vulnerability disclosed


10. REFERENCES

Original Advisory URL: http://yehg.net/lab/pr0js/advisories/[vanilla_forums-2.0.17.5]_cross_site_scripting
Github Issue Report: https://github.com/vanillaforums/Garden/issuesearch?state=closed&q=xss#issue/750
Vendor Commit: https://github.com/vanillaforums/Garden/commit/0a22506c76ac419d390d5d1bde5ec5f48b195358
Vendor Release: http://vanillaforums.org/discussion/14397/vanilla-2.0.17-released/
XSS (owasp): http://www.owasp.org/index.php/Cross-site_Scripting_(XSS)
CWE-79: http://cwe.mitre.org/data/definitions/79.html


#yehg [2011-02-22]

updated: 2011-02-25, - added CVE