Protostar Stack4

The application is a super simple buffer overflow. The c code is only a few lines. The objective is to change the return address to the win function. C Code #include <stdlib.h> #include <unistd.h> #include <stdio.h> #include <string.h>…

Protostar Stack 3

Vulnerable Code #include <stdlib.h> #include <unistd.h> #include <stdio.h> #include <string.h> void win(){ printf("code flow successfully changed\n"); } int main(int argc, char **argv){ volatile int (*fp)(); char buffer[64]; fp = 0; gets(buffer); if(fp) { printf("calling…

Protostar Stack2

Challenge Source Code #include <stdlib.h> #include <unistd.h> #include <stdio.h> #include <string.h> int main(int argc, char **argv) { volatile int modified; char buffer[64]; char *variable; variable = getenv("GREENIE"); if(variable == NULL) { errx(1, "please set the GREENIE environment…

Protostar Stack1

easy buffer overflow compare statement in assembly for 1 payload needs to start with 1 buffsize found to be 64 bits filler 64 characters long: 'a'*64 hard coded canary as "0x61626364" little endian: 'dcba' final payload python exploit1.py | ./stack1 bufferSize = 64; filler = 'a' * bufferSize firstCompare = '1' secondCompare = 'abcd'…