Code Execution 04

In this exercise, you will explore the security implications of PHP's assert function when improperly used. The lab demonstrates how injecting a single or double quote can break the syntax, revealing that PHP is evaluating the code. You will learn how to correct the syntax and inject a payload that allows you to execute PHP functions such as phpinfo(), which provides detailed configuration information of the PHP environment.

The lab also guides you to replace phpinfo() with more impactful functions like system() to execute system commands. This exercise emphasizes the importance of understanding how PHP's assert function works and the potential risks associated with its misuse, especially in PHP versions prior to 7.0. The lab concludes by highlighting that these methods are largely mitigated in PHP 7 and above, due to changes in how assert handles string arguments.