source: https://www.securityfocus.com/bid/47073/info

Claroline is prone to multiple HTML-injection vulnerabilities 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.

Claroline 1.10 is vulnerable; other versions may also be affected. 

"><script>alert(0)</script>