Course

In this exercise, you will delve into techniques for bypassing suffixes added to user inputs, a common strategy in Local File Inclusion (LFI) and Remote File Inclusion (RFI) vulnerabilities. The lab demonstrates the usage of NULL bytes to nullify unwanted suffixes and highlights URL manipulation methods such as appending `&blah=` or `?blah=` to achieve similar effects. This is particularly relevant for understanding how older versions of PHP handled paths and how modern versions have addressed these issues.

The lab's code simulates the behavior of older PHP versions, specifically before the fix introduced in PHP 5.3.4. You will see how paths with NULL bytes were previously treated and how exploiting this could lead to arbitrary file reads or even command execution. By understanding these bypass techniques, you can better appreciate the importance of input validation and the evolution of PHP's security measures.