#!/usr/bin/python
# intx.py
# Ecava IntegraXor Remote ActiveX Buffer Overflow PoC
# Jeremy Brown
# December 2010
# http://www.integraxor.com/
#
# There is a stack-based buffer overflow in IntegraXor that can be triggered
# by passing an overly large value to the "save" method of the IntegraXor.Project
# control located in igcomm.dll. This control is marked both safe for scripting
# and safe for initialization.
#
# .text:100027C1 push eax ; lpString2
# .text:100027C2 lea eax, [esp+84Ch+String1]
# .text:100027C6 push eax ; lpString1
# .text:100027C7 call ds:lstrcpyW
# .text:100027CD lea ecx, [esp+848h+String1]
# .text:100027D1 push ecx
# .text:100027D2 call SplitPath
# .text:100027D7 add esp, 4
# .text:100027DA lea ecx, [esp+848h+var_83C]
# .text:100027DE call ds:??0?$basic_string@_WU?$char<truncated>
# .text:100027E4 cmp dword ptr [esi+20h], 8
# .text:100027E8 jb short loc_100027EF
# .text:100027EA mov esi, [esi+0Ch]
# .text:100027ED jmp short loc_100027F2
#
# The vulnerable code in this block passes String1 (dest) and lpString2 (src)
# to lstrcpyW() without validating the length of lpString2. lstrcpyW() then
# copies lpString2 byte for byte into String1 (1024 bytes wchar buffer) and
# adds a terminating NULL byte to the end.
#
# If you attach a debugger and set a breakpoint on 100027CD, you can see an
# exception registration record is stored before the return address:
#
# ESP+83C > 00420042 B.B. Pointer to next SEH record
# ESP+840 > 00420042 B.B. SE handler
# ESP+844 > FFFF0000 ..��
# ESP+848 > 10007916 xxxx RETURN to igcom.10007916 from igcom.10002770
#
# I wasn't able to find any useable unicode compatible PPRs. We can overwrite
# the return address, but it will exit with a c0000409 code (/GS exception).
#
# Tested Ecava IntegraXor 3.5.3900.5 on Windows
#
# Fixed version: 3.5.3900.10
#