Code Execution 02
This exercise is one of our challenges on Code Execution
In this lab, you will learn about a PHP code injection vulnerability that exploits the usort function in conjunction with create_function. Developers often use usort to dynamically generate sorting functions based on user input. If the input is not adequately filtered and validated, it can lead to code execution vulnerabilities. By injecting specific payloads, we can manipulate the sorting function to execute arbitrary code on the server.
The lab demonstrates how to close the dynamically generated function properly and inject code without breaking the existing structure. This kind of vulnerability was notably present in PHPMyAdmin (CVE-2008-4096), highlighting the importance of input validation and filtering in web applications.