WordPress Plugin Rich Widget is prone to a vulnerability that lets attackers upload arbitrary files because the application fails to properly sanitize user-supplied input. An attacker can exploit this vulnerability to upload arbitrary code and run it in the context of the webserver process. This may facilitate unauthorized access or privilege escalation; other attacks are also possible. WordPress Plugin Rich Widget version 0.2.4 is vulnerable; other versions may also be affected.
Restrict access to test.html (e.g. via .htaccess) or disable the plugin until a fix is available