# Utumno wargame: Level 0

# ssh utumno0@utumno.labs.overthewire.org
utumno0@utumno.labs.overthewire.org's password:
7574756d6e6f30

utumno0@melissa$ file /utumno/utumno0
/utumno/utumno0: setuid executable, regular file, no read permission
utumno0@melissa$ mkdir /tmp/u0
utumno0@melissa$ cd !$
utumno0@melissa$ cat hook.c
#include <stdio.h>
#include <unistd.h>

int puts(const char *s){
        char *p;
        int i;
        write(1,"Hooked: puts function\n",22);
        printf("%x-%x-%x-%x-%x-%x-%x-%x-%x-%x-%x-%x\n");
        for(i=0x80484bb-11;i<0x80484bb+11;i++){
                p=i;
                printf("%c",*p);
        }

}
utumno0@melissa$ gcc -m32 -fPIC -c hook.c -o hook.o && ld -shared -m elf_i386 -o hook.so hook.o -ldl
utumno0@melissa$ strace -s 100 -E LD_PRELOAD=./hook.so -e trace=write /utumno/utumno0
[ Process PID=11490 runs in 32 bit mode. ]
write(1, "Hooked: puts function\n", 22Hooked: puts function
) = 22
write(1, "f7fdb278-16-0-ffffd738-f7ff3f70-1-f7fdb200-ffffd7e4-f7fd0ff4-ffffd738-80483d1-80484bb\n", 86f7fdb278-16-0-ffffd738-f7ff3f70-1-f7fdb200-ffffd7e4-f7fd0ff4-ffffd738-80483d1-80484bb
) = 86
write(1, "61617468616579696577\0Read me! :P", 3261617468616579696577Read me! :P) = 32