The host is running A Really Simple Chat and is prone to multiple cross site scripting vulnerabilities.
Successful exploitation will allow attacker to inject arbitrary web script or HTML by executing arbitrary scripts. Impact Level: Application
No solution or patch was made available for at least one year since disclosure of this vulnerability. Likely none will be provided anymore. General solution options are to upgrade to a newer release, disable respective features, remove the product or replace the product by another one.
The flaws are due to improper validation of user supplied data in the 'arsc_link' parameter in dereferer.php and 'arsc_message' parameter in login.php, which allow attacker to execute arbitrary scripts.
A Really Simple Chat version 3.3 rc2.