vBulletin 4.0.8 PL1 – Cross-Site Scripting Filter Bypass within Profile Customization
# Exploit Title: vBulletin 4.0.8 PL1 - XSS Filter Bypass within Profile Customization # Google Dork: "Powered by vBulletin Version 4.0.8" -"vBulletin.com is now powered by" # Date: 20th November 2010 # Author: MaXe # Software Link: Commercial software. # Version: 4.0.8 PL1 # Screenshot: See attachment. # Tested on: Windows and Linux (Server) + IE6 (Client). vBulletin - XSS Filter Bypass within Profile Customization Versions Affected: 4.0.8 PL1 (3.8.* is not vulnerable.) Info: Content publishing, search, security, and more - vBulletin has it all. Whether it's available features, support, or ease-of-use, vBulletin offers the most for your money. Learn more about what makes vBulletin the choice for people who are serious about creating thriving online communities. External Links: http://www.vbulletin.com Credits: MaXe (@InterN0T) -:: The Advisory ::- vBulletin is prone to a Persistent Cross Site Scripting vulnerability within the Profile Customization feature. If this feature is not enabled the vulnerability does not exist and the installation of vBulletin is thereby secure. Within the profile customization fields, it is possible to enter colour codes, rgb codes and even images. The image url() function does not sanitize user input in a sufficient way causing vBulletin to be vulnerable to XSS attacks. With the previous patch for vBulletin 4.0.8 PL1, most attacks were disabled however it is possible to bypass this filter and inject data which is then executed effectively against though not limited to Internet Explorer 6. Proof of Concept: url(vbscript:msgbox("X/SS")) -:: Solution ::- Update vBulletin to version: 4.0.8 PL2 Disclosure Information: - Vulnerability found and researched: 18th November 2010 - Disclosed to vendor (Internet Brands): 18th November - Patch from Vendor available: 19th November - Disclosed at: InterN0T, Full Disclosure, Bugtraq and Exploit: 20th November References: http://forum.intern0t.net/intern0t-advisories/3398-vbulletin-4-0-8-pl1-cross-site-scripting-filter-bypass-within-profile-customization.html http://forum.intern0t.net/intern0t-advisories/3349-vbulletin-4-0-8-persistent-cross-site-scripting-via-profile-customization.html |