SMASH THE STACK LEVEL2
Date: December 1, 2014
time to play
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level2@io:/levels$ ./level02 source code is available in level02.c |
let’s read what it says
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level2@io:/levels$ cat level02.c //a little fun brought to you by bla #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <setjmp.h> void catcher(int a) { setresuid(geteuid(),geteuid(),geteuid()); printf("WIN!\n"); system("/bin/sh"); exit(0); } int main(int argc, char **argv) { puts("source code is available in level02.c\n"); if (argc != 3 || !atoi(argv[2])) return 1; signal(SIGFPE, catcher); return abs(atoi(argv[1])) / atoi(argv[2]); } level2@io:/levels$ |
first function catcher and it trigger the suid and drop the bash nice this is what we want