PHP

Introduction Context Explanation Numberizer is a seemingly simple web-based CTF challenge, where users are required to submit five numbers in an HTML form such that the sum of all the numbers is negative. However, the challenge implements input validation and sanitization mechanisms to prevent trivial solutions like using negative numbers. Our goal is to bypass these controls and successfully achieve the required negative sum to retrieve the flag. Solution Analyzing the Code and Validation Mechanisms The provided PHP source code implements a number of validation checks:...