Introduction

Node.JS is a Cross Platform and Runtime Environment Where one can execute javascript code, outside the Web Browser. Node.JS is Very helpful but it has a couple of Killing features which make it very dangerous and hazardous for a web application. In this tutorial we are going to discuss one of them, Command Execution in Node.JS, You Folks must know what is Command Execution but just to be sure I’d like to tell you, Command Execution Vulnerabilities Allow an Attacker to run arbitrary Commands on a System through the Vulnerable Environment. I guess its enough for introcution.

Vulnerable Code

Here is vulnerable code which demonstrates the vulnerability in node js.

I’ll simply give the overview about where exactly its getting hectic. We are using exec function from child_process library, and executing parsedUrl.query.command, that is not getting filtered. Hence an attacker can execute any arbitrary commdn in order to hack into system. Let’s Save it and run it. Here is my script running.

Code is working without any error, let’s try to visit the url 127.0.0.1:8888 in browser as it is listening on port 8888.

Whoa, we got it working. Now its time to do some evil stuff. Let’s try to execute systeminfo, PING & Some other commands , that displays information about a computer.

#fig1

#fig2

#fig3

Okay fine, as it is clear from the above POC that its working exactly fine. In this context a developer must be careful while working with Node.JS files as its kinda more hectic and Evil than other languages.

About the Author

Muhammad Adeel is a Security researcher & Founder at Whitehat Conference Pakistan, he Blogs at http://urdusecurity.blogspot.com

Node JS & Command Execution

Uploaded by: Adeel Chaudhary

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Category: Command Execution, Hacking in Urdu, Node Js, WebAppSec

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