CTF writeups
Capture the flag
haadi@portfolio:~$ ls -1 *.md
9 CTF writeups
- 2026.05.17CTF writeupTJCTF 2026
Treasure Hunt
A flag split across four places, a hidden DOM element, a cookie and the site's images, and why the hidden attribute hides nothing from an attacker.
Web · Easy · 109 pts
- 2026.05.07CTF writeuppicoCTF 2026
Shared Secrets
Diffie-Hellman is only as strong as its private exponents. Once one leaks, the shared secret falls with it.
Cryptography · Easy
- 2026.05.07CTF writeuppicoCTF 2026
StegoRSA
An RSA private key hex-encoded into an image's metadata, and why hiding a key is not the same as protecting it.
Crypto · Steganography · Easy
- 2026.05.05CTF writeuppicoCTF 2025
Crack the Gate 1
A ROT13 developer comment points to a custom request header that walks straight past the login.
Web exploitation · Easy
- 2026.05.05CTF writeuppicoCTF 2025
Old Sessions
Session hijacking made trivial: sessions that never expire, and an endpoint that lists everyone's tokens, including the admin's.
Web exploitation · Easy
- 2026.05.03CTF writeuppicoCTF 2026
Binary Digit
A file of ones and zeros that becomes an image once you stop assuming it's text.
Forensics · Easy
- 2026.05.03CTF writeuppicoCTF 2025
Flag in Flame
A suspicious 'log file' that's really a Base64-encoded image carrying a hex-encoded flag, two layers, peeled back one at a time.
Forensics · Easy
- 2026.05.03CTF writeuppicoCTF 2025
Hidden in Plainsight
A double-Base64 passphrase in JPG metadata that unlocks a steghide payload, misdirection by design.
Forensics · Steganography · Easy
- 2026.05.03CTF writeuppicoCTF 2025
Riddle Registry
Garbled PDF, revealing metadata: pulling an encoded flag out of a document's Info dictionary.
Forensics · Easy