Whoogle Search is a self-hosted metasearch engine. In versions 0.8.3 and prior, the "element" method in "app/routes.py" does not validate the user-controlled "src_type" and "element_url" variables and passes them to the "send" method which sends a "GET" request on lines 339-343 in "requests.py". The returned contents of the URL are then passed to and reflected back to the user in the "send_file" function on line 484, together with the user-controlled "src_type", which allows the attacker to control the HTTP response content type leading to a cross-site scripting vulnerability. An attacker could craft a special URL to point to a malicious website and send the link to a victim. The fact that the link would contain a trusted domain (e.g. from one of public Whoogle instances) could be used to trick the user into clicking the link. The malicious website could, for example, be a copy of a real website, meant to steal a person’s credentials to the website, or trick that person in another way. Version 0.8.4 contains a patch for this issue.