Escape_303

MediumWeb

Overview

The challenge presents a file search service designed to check for files and directories on a server. Despite the developer's attempt to implement restrictions, sensitive information is being leaked from a flag file located at /(random_string)_flag.txt. Our goal is to identify the vulnerability and retrieve the flag.
Flag format: Flag{}

Lab Details

Prerequisites & Requirements

  • Basic understanding of web security concepts, particularly command injection vulnerabilities
  • Familiarity with PHP syntax and behavior
  • Knowledge of Linux shell commands

What will you learn?

  • Analyze PHP source code for security vulnerabilities
  • Identify and exploit command injection flaws
  • Bypass input sanitization mechanisms
  • Understand the limitations of escapeshellcmd() in preventing argument injection

Tools

  • Webhook.site for hosting payloads
  • Web Browser for interacting with the challenge
  • cURL for testing and exploitation

Job Positions

Application Security Engineer

Tags

Command InjectionInput ValidationPhpSource Code Review