# Host Header Injection 1. Change the host header ``` GET /index.php HTTP/1.1 Host: evil-website.com ... ``` 2. Duplicating the host header ``` GET /index.php HTTP/1.1 Host: vulnerable-website.com Host: evil-website.com ... ``` 3. Add line wrapping ``` GET /index.php HTTP/1.1 Host: vulnerable-website.com Host: evil-website.com ... ``` 4. Add host override headers ``` X-Forwarded-For : evil-website.com X-Forwarded-Host : evil-website.com X-Client-IP : evil-website.com X-Remote-IP : evil-website.com X-Remote-Addr : evil-website.com X-Host : evil-website.com ``` How to use? In this case im using "X-Forwarded-For : evil.com" ``` GET /index.php HTTP/1.1 Host: vulnerable-website.com X-Forwarded-For : evil-website.com ... ``` 5. Supply an absolute URL ``` GET https://vulnerable-website.com/ HTTP/1.1 Host: evil-website.com ... ``` Source: https://portswigger.net/web-security/host-header/exploiting