[Misc 200] [a-z().]

Description

if (eval(your_code) === 1337) console.log(flag);

http://(redacted) (server/Dockerfile)

• a-z.tar.xz

Intended Solution

• curl "http://(target)/?code=eval%28%28typeof%28this%29%29.constructor%28%28typeof%28this%29%29.length.constructor%28true%29%29.concat%28%28typeof%28this%29%29.big.name.length%29.concat%28%28typeof%28this%29%29.big.name.length%29.concat%28true.constructor.name.length%29%29"

(typeof(this)).constructor => String
(typeof(this)).length.constructor => Number
(typeof(this)).length.constructor(true) => 1
(typeof(this)).big.name.length => 3
true.constructor.name.length => 7

Flag

HarekazeCTF{sorry_about_last_year's_js_challenge...}