Path 19: CTF Challenges — KashSec Academy

A standalone Capture The Flag zone — self-contained hands-on puzzles across Web, API, Crypto, Forensics, AI, Misc, and Linux privesc. No new material, just applying what you've learned under pressure. 24 free lessons, all levels level, starting with "Welcome to the CTF Zone"

Level: All levels · 24 lessons · Free, no account needed.

Lessons in this path

  1. Welcome to the CTF Zone — Flag format, categories, and how to actually approach a challenge.
  2. Web — The IDOR Hunt — Spot and explain a broken access control flaw. Easy.
  3. Crypto — The Layered Cipher — Peel back two stacked encodings by hand. Easy.
  4. Forensics — The Log Hunt — Find the successful brute-force in a sea of noise. Easy.
  5. Web — Forge the Token — Exploit alg=none to forge admin access. Medium.
  6. Misc — Hidden in Plain Sight — Reassemble a flag scattered across HTTP headers. Medium.
  7. Crypto — Break the XOR Cipher — A real known-plaintext attack on repeating-key XOR. Hard.
  8. Linux — The Privesc Puzzle — Turn a passwordless sudo rule into a root shell. Medium.
  9. API — The Order Number That Wasn't Yours — Classic BOLA against a JSON API. Easy.
  10. API — The Profile Update That Went Too Far — Escalate privilege through an unrestricted PATCH endpoint. Medium.
  11. API — Locked Out, Sort Of — Spoof X-Forwarded-For to blow past a login lockout. Hard.
  12. Web — Crack the Secret — Brute-force a guessable HS256 HMAC secret, then forge admin. Medium.
  13. Web — The Wrong Kind of Trust — Turn a public RSA key into an HMAC secret. Hard.
  14. Web — A Key of Your Choosing — Path-traverse the kid header into a known, empty signing key. Hard.
  15. Web — Name Your Own Price — A checkout that trusts client-submitted pricing. Easy.
  16. Web — The Coupon That Wouldn't Quit — A check-then-act race condition in coupon redemption. Medium.
  17. Web — Two Steps Forward, Zero Back — Skip straight to checkout confirmation, no payment required. Hard.
  18. AI — Leak the System Prompt — Direct prompt injection against a support chatbot. Easy.
  19. AI — The Ambush in the Article — Plant an instruction inside content another user's AI assistant will read. Medium.
  20. AI — Jailbreak the Judge — Bypass a hardened refusal with a fictional-story framing. Hard.
  21. Crypto — Small Primes, Big Problem — Factor an undersized RSA modulus by hand and recover the private key. Hard.
  22. Forensics — The EXIF Trail — A leaked photo's metadata reveals more than a flag. Easy.
  23. Linux — The Binary That Betrayed Root — A SUID-root Python interpreter is a root shell in disguise. Medium.
  24. Solution Write-ups: The Template Every Good CTF Player Uses — The six-part structure that turns a solve into a portfolio piece.