The remote web server is hosting an application that is vulnerable to a cross-site scripting attack.
The remote web server is hosting SilverStripe CMS. The installed version of SilverStripe is earlier than 2.3.5. Such versions are potentially affected by a persistent cross-site scripting vulnerability becase the application fails to properly sanitize user-supplied input to the 'CommenterURL' parameter in the comment posting mechanism. An attacker could exploit this flaw in order to execute arbitrary script code in a user's browser.
Upgrade to SilverStripe 2.3.5 or later.