What are Command Injection Attacks?

Command Injection is an attack method in which a hacker alters dynamically generated content on a web page by entering shell commands into strings that are passed to the system shell. By manipulating variables that reference files with “include” statements, an attacker can trick the web server into executing shell commands or codes, leading to data theft, data manipulation, and server compromise.

Command Injection Example

Here is a simple example of a Command Injection attack:

             // User input
             ; ls
     
             // Server command
             ping -c 4 192.168.1.101; ls
             

In this example, the attacker injects the 'ls' command to list the files in the current directory.

Prevention

Preventing Command Injection attacks involves proper input validation, sanitization, and secure application design. This includes:

• Input validation: Validate user input by only accepting expected values.
• Sanitize input: Remove or replace special characters from user input.
• Secure application design: Applications should be designed to not allow Command Injection.