Expinion.Net Member Management System 'REF_URL' Parameter Cross-Site Scripting Vulnerability

Summary
The host is running Member Management System and is prone to cross site scripting vulnerability.
Impact
Successful exploitation will allow remote attackers to insert arbitrary HTML and script code, which will be executed in a user's browser session in the context of an affected site. Impact Level: Application
Solution
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.
Insight
The flaw is due to improper validation of user-supplied input via the 'REF_URL' parameter to admin/index.asp, Which allows attacker to execute arbitrary HTML and script code on the user's browser session in the security context of an affected site.
Affected
Expinion.Net Member Management System version 4.0 and prior.
References