WordPress Amazon Associate Plugin 'callback' Parameter XSS Vulnerability

Summary
This host is running WordPress Amazon Associate Plugin and is prone to cross site scripting vulnerability.
Impact
Successful exploitation will allow attacker to insert arbitrary HTML and script code, which will be executed in a user's browser session in the context of an affected site when the malicious data is being viewed. 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
Input passed via the 'callback' parameter to wp-content/plugins/wordpress-amazon-associate/servlet/index.php is not properly sanitised before it is returned to the user.
Affected
WordPress Amazon Associate Plugin version 2.0 and prior
References