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] --------------------------------- Best regards, YGN Ethical Hacker Group Yangon, Myanmar http://yehg.net Our Lab | http://yehg.net/lab Our Directory | http://yehg.net/hwd