Abusing file inclusions and uploads
As we saw in Chapter 4, Finding Vulnerabilities, file inclusion vulnerabilities occur when developers use poorly validated input to generate file paths and use those paths to include source code files. Modern versions of server-side languages, such as PHP since 5.2.0, have by default disabled the ability to include remote files, so it has been less common to find an RFI since 2011.
In this recipe, we will first upload a couple of malicious files, one of them is a webshell (a web page capable of executing system commands in the server), and then execute them using local file inclusions.
Getting ready
We will use Damn Vulnerable Web Application (DVWA) in the vulnerable_vm for this recipe and will have it with a medium level of security, so let's set it up:
Navigate to
http://192.168.56.102/dvwa.Log in.
Set the security level to medium: Go to DVWA Security, select medium in the combo box and click on Submit.
We will upload some files to the server, but you need...
