1. OVERVIEW
The BlastChat's chat client Component of Joomla 1.x, Joomla 1.5.x, Mambo 4.5, Mambo 4.6, Drupal 6
was vulnerable to Cross Script Scripting (XSS) Vulnerability.
2. PRODUCT DESCRIPTION
The BlastChat Chat Client Component is a widely-used Blastchat chat client component designed for website communities
from the smallest personal websites to the huge megasites who desire to provide their members and visitors
with a superb chat experience. The client chat component is available in multiple CMSes including
Joomla 1.x, Joomla 1.5.x, Mambo 4.5, Mambo 4.6, and Drupal 6.
BlastChat has currently been serving chat to over 50.000+ websites.
3. VULNERABILITY DESCRIPTION
The BlastChat's chat client Component does not properly escape "Itemid" parameter, which leads to Cross Site Scripting vulnerability.
For more information about this kind of vulnerability, see OWASP Top 10 - A2, WASC-8 and CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
4. VERSIONS AFFECTED
Versions: 3.3 and lower
5. PROOF-OF-CONCEPT/EXPLOIT
URL: /index.php?option=com_blastchatc&Itemid=-999
Affected Parameter: Itemid
http://yehg.net/lab/pr0js/advisories/joomla/com_blastchatc_xss(Itemid).jpg
6. IMPACT
As this is a multi-user chat application "component", the impact of XSS is huge, ranking from cookie theft to mass client exploits.
7. SOLUTION
Upgrade to version 3.4
8. VENDOR
Blastchat
http://www.blastchat.com
9. CREDIT
This vulnerability was discovered by Aung Khant, http://yehg.net, YGN Ethical Hacker Group, Myanmar.
10. DISCLOSURE TIME-LINE
08-11-2010: discovered vulnerability
08-11-2010: notified vendor
08-11-2010: vendor fixed vulnerability
08-14-2010: vendor released patched version - 3.4
08-26-2010: vulnerability disclosed
11. REFERENCES
Original Advisory URL: http://yehg.net/lab/pr0js/advisories/joomla/[com_blastchatc]_cross_site_scripting
What XSS Can Do: http://yehg.net/lab/pr0js/view.php/What%20XSS%20Can%20Do.pdf
XSS FAQs: http://www.cgisecurity.com/articles/xss-faq.shtml
XSS (wiki): http://en.wikipedia.org/wiki/Cross-site_scripting
XSS (owasp): http://www.owasp.org/index.php/Cross-site_Scripting_(XSS)
OWASP Top 10: http://www.owasp.org/index.php/Category:OWASP_Top_Ten_Project
CWE-79: http://cwe.mitre.org/data/definitions/79.html