vBulletin BB Code Script Insertion Vulnerability

                                                vBulletin 3.x / 4.x

MaXe has reported a vulnerability in vBulletin, which can be exploited by malicious users to conduct script insertion attacks.

The vulnerability exists in the parsing of BB Code when creating content that uses custom tags. This can be exploited to insert arbitrary HTML and script code, which will be executed in a user's browser session in context of an affected site when the malicious data is being viewed.

Successful exploitation requires that "Custom BB Code" tags utilize HTML tags without quotation in e.g. "href" attribute of the "a" tag.

The vulnerability is reported in version 3.8.4 PL2 and 4.0.3. Other versions may also be affected.

http://forum.intern0t.net/intern0t-advisories/2528-vbulletin-3-8-4-pl2-insecure-custom-bbcode.html