Required Knowledge :
- what are file descriptors
- default file desciptors for stdin
ssh [fd@pwnable.kr](mailto:fd@pwnable.kr) -p2222
On carefully looking at the code, we can see that we need to read LETMEWIN string from the file desciptor fd which is determined by the argument of the binary.
So we can make fd = 0 to read from stdin and then we can enter the required string there.
Note : the argument here is 4660 i.e int(0x1234) becausue it is substracted in the code.