Csaw 2014 Bo Writeup

LeeDoHyun · March 29, 2020

아주아주아주아주아주아주아주아주아주아주아주 쉬운문제입니다.

바이너리를 다운받고 문제를 풀려고 분석하는데 플래그가 나와버렸습니다.

int __cdecl challenge(int fd)
{
  int v2; // [esp+18h] [ebp-90h]
  unsigned int v3; // [esp+98h] [ebp-10h]
  unsigned int v4; // [esp+9Ch] [ebp-Ch]

  v4 = __readgsdword(0x14u);
  v3 = 0;
  ctf_writes(fd, "Welcome to CSAW CTF!\n");
  ctf_writes(fd, "Time to break out IDA Demo and see what's going on inside me.  :]\n\n");
  ctf_readsn(fd, &v2, 132);
  if ( v3 && v3 > 0x7E7E7E7E )
    ctf_writes(fd, "flag{exploitation_is_easy!}");
  return 0;
}

Twitter, Facebook