Description
Cookie Monster’s login page sets a `secret_recipe` cookie that already contains the flag. Harvest the cookie and decode it from Base64.
Setup
Submit any username/password combination; authentication isn’t enforced.
Open developer tools → Application/Storage → Cookies to inspect the response cookies.
echo "cGljb0NURntjMDBrMWVfbTBuc3Rlcl9sMHZlc19jMDBraWVzXzc3MUQ1RUIwfQ==" | base64 -d
Solution
- Step 1Dump the cookieLook for `secret_recipe`. Its value is a URL-encoded Base64 blob ending in `%3D%3D`. Decode the percent-encoding first if needed.
- Step 2Decode the blobEither paste into CyberChef or pipe through `base64 -d` to reveal picoCTF{c00k1e_m0nster_l0ves_c00kies_771D5EB0}.
Flag
picoCTF{c00k1e_m0nster_l0ves_c00kies_771D5EB0}
No login bypass is necessary; the secret is literally in the cookie jar.