The host is running Microsoft .NET and is prone to Cross-Site Scripting Vulnerability.
Successful exploitation could allow attackers to conduct cross-site scripting attacks against the form control via the __VIEWSTATE parameter.
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 flaw is due to error in the handling of the '__VIEWSTATE' parameter in 'ASP.NET', which does not properly handle an unencrypted view state.
Microsoft .NET version 3.5 and prior.