OS Command Injection

Occurs when server-side code (PHP) in web application makes a system call on hosting machne.

Allows attacker to take advantage of that made system commands on the server.

It opens up many options for the attacker by doing enumeration through executing commands like whoami

Worst thing an attacker could do is spawn reverse shell to become the user that the web server is running as.

When system command made to server doesn't return the response to the user in HTML document.Instead it returns response to user.

Active command injection occurs when you can see the response from the system call.

Like this pic above ^
It's suppose to be a webshell,
but then it allowed me to see the output of it.
Therefore I can see the files, the user info through /etc/passwd

Reverse Shells Reverse Shell