ELF Format String - Root-Me Writeup

Overwriting global variables in memory using printf %n format specifiers.

🖥️ Challenge / Machine Info

  • Platform: root-me
  • Name / Title: elf-fmt
  • Difficulty: Medium
  • Target OS / Environment: Binary
  • Key Vulnerability Focus: Format String / %n memory overwrite

Walkthrough

  1. Find global variable memory address.
  2. Inject a custom payload utilizing %n format specifier to overwrite the variable value in memory, triggering shell execution.