A reflected cross-site scripting (XSS) in Nagios XI 5.7.1 can result in an attacker performing malicious actions to users who open a maliciously crafted link or third-party web page.
To exploit vulnerability, someone could use a GET request to 'http://[server]/includes/components/ccm/' by manipulating 'returnUrl' parameter in the request body to impact users who open a maliciously crafted link or third-party web page.
http://[server]/includes/components/ccm/?cmd=modify&id=1&page=1&returnUrl=%22%3C/script%3E%3Cscript%3Ealert(document.domain)%3C/script%3E&type=host
