Some vulnerabilities have been reported in vBulletin, which can be exploited by malicious people to conduct cross-site scripting and script insertion attacks.

1) Some unspecified input isn't properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

2) An input validation error in the attachment handling can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site by uploading a specially crafted PDF document containing embedded HTML and script code.

Successful exploitation requires that the malicious PDF document is accessed directly in the Microsoft Internet Explorer browser.

3) An error in the restriction of accessing global.php directly can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site by URL encoding the global.php filename in the URL and setting certain parameters.

Solution
Update to version 2.3.10, 3.0.15, 3.5.5, or 3.6.0 (the releases were updated 2006-08-03 to include fixes for vulnerability #2).
Further details available to Secunia VIM customers

Provided and/or discovered by
1) Reported by the vendor.
2) Stefan, EnigmaGroup
3) imei addmimistrator

Changelog
Further details available to Secunia VIM customers

Original Advisory
Jelsoft Enterprises:
http://www.vbulletin.com/forum/showthread.php?t=194072
http://www.vbulletin.com/forum/showthread.php?t=194063
http://www.vbulletin.com/forum/showthread.php?t=194062
http://www.vbulletin.com/forum/showthread.php?t=194061

imei addmimistrator:
http://www.kapda.ir/advisory-397.html

Deep Links
Links available to Secunia VIM customers