source: http://www.securityfocus.com/bid/4182/info

Ikonboard is a Web Bulletin Board Service (BBS) software package written in Perl which runs on Unix and Linux variants.

Ikonboard allows users to include images in forum messages using image tags, with the following syntax:

[img]url of image[/img]

It is possible to inject arbitrary script code into forum messages via these image tags. Script code will be executed in the browser of the user viewing the forum message, in the context of the website running the vulnerable software. This may allow an attacker to steal cookie-based authentication credentials.

Reports have indicated that this may be an issue in older versions.

It has also been reported that Ikonboard 3.1.1 is also vulnerable to this issue.

[img]javasCript:alert('Hello world.')[/img]
[IMG]javascript:alert(document.cookie).gif[/IMG]