RFI (Remote File Inclusion) : Website Hacking Tutorial

Remote File Inclusion (RFI) is a type of vulnerability most often found on websites. It allows an attacker to include a remote file, usually through a script on the web server. The vulnerability occurs due to the use of user-supplied input without proper validation. This can lead to something as minimal as outputting the contents of the file, but depending on the severity, to list a few it can lead to:
Code execution on the web server
Code execution on the client-side such as JavaScript which can lead to other attacks such as cross site scripting (XSS).
Denial of Service (DoS)
Data Theft/Manipulation