# Bbbbloat - picoCTF 2022 - CMU Cybersecurity CompetitionReverse Engineering, 300 Points
## Description
![‏‏info.JPG](images/info.JPG) ## Bbbbloat Solution
By decompiling the [attched binary](./bbbbloat) using [Ghidra](https://github.com/NationalSecurityAgency/ghidra) we can see the following on ```FUN_00101307``` function:```c
undefined8 FUN_00101307(void)
{  char *__s;  long in_FS_OFFSET;  int local_48;  undefined8 local_38;  undefined8 local_30;  undefined8 local_28;  undefined8 local_20;  long local_10;   local_10 = *(long *)(in_FS_OFFSET + 0x28);  local_38 = 0x4c75257240343a41;  local_30 = 0x3062396630664634;  local_28 = 0x35613066635f3d33;  local_20 = 0x4e603234363266;  printf("What\'s my favorite number? ");  __isoc99_scanf();  if (local_48 == 0x86187) {    __s = (char *)FUN_00101249(0,&local_38);    fputs(__s,stdout);    putchar(10);    free(__s);  }  else {    puts("Sorry, that\'s not it!");  }  if (local_10 != *(long *)(in_FS_OFFSET + 0x28)) {                    /* WARNING: Subroutine does not return */    __stack_chk_fail();  }  return 0;}```
We can see the binary ask for the number ```0x86187``` (```549255```) as input, Let's run it and insert this input:```console┌─[evyatar@parrot]─[/pictoctf2022/reverse_engineering/Bbbbloat]└──╼ $ ./bbbbloat What's my favorite number? 549255picoCTF{cu7_7h3_bl047_2d7aeca1}```
And we get the flag ```picoCTF{cu7_7h3_bl047_2d7aeca1}```.