🥋Form - ImaginaryCTF 2023

Source

16KB

Analysis

vuln.c

int __cdecl __noreturn main(int argc, const char **argv, const char **envp)
{
  char *format; // [rsp+0h] [rbp-20h] BYREF
  char *s; // [rsp+8h] [rbp-18h]
  FILE *stream; // [rsp+10h] [rbp-10h]
  unsigned __int64 v6; // [rsp+18h] [rbp-8h]

  v6 = __readfsqword(0x28u);
  s = (char *)malloc(0x20uLL);
  format = (char *)malloc(0x20uLL);
  setbuf(stdin, 0LL);
  setbuf(_bss_start, 0LL);
  stream = fopen("flag.txt", "r");
  fgets(s, 32, stream);
  fgets(format, 32, stdin);
  s = (char *)&format;
  if ( strlen((const char *)&format) <= 0x17 )
    printf(format);
  _exit(0);
}