鬼仔's Blog

信息来源：安全焦点

Sowhat of Nevis Labs
日期: 2007.01.09

http://www.nevisnetworks.com
http://secway.org/advisory/20070109EN.txt
http://secway.org/advisory/20070109CN.txt

CVE: 暂无

厂商

Sina Inc.

受影响的版本：
Sina UC <=UC2006

Overview:
新浪UC是中国非常流行的IM工具之一

http://www.51uc.com

细节:

漏洞的起因是Sina UC的多个ActiveX控件的参数缺乏必要的验证，攻击者构造恶意网页，可以远程完全控制安装了Sina UC
的用户的计算机，

多个控件存在栈溢出问题，包括但不限于：

1. clsid:77AE4780-75E0-4CB0-A162-D1BBE3D50384
C:\Program Files\sina\UC\ActiveX\BROWSER2UC.dll

Sub SendChatRoomOpt (
ByVal astrVerion As String ,
ByVal astrUserID As String ,
ByVal asDataType As Integer ,
ByVal alTypeID As Long
)

当第1个参数是一个超常字符串时，发生栈溢出，SEH被覆盖，攻击者可以执行任意代码

调试信息：
(534.674): Access violation – code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000041 ebx=00000000 ecx=0000037d edx=00000002 esi=02849ada edi=00130000
eip=02b97c76 esp=0012d2cc ebp=0012d2d4 iopl=0 nv up ei pl nz ac pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=0038 gs=0000 efl=00000212
*** WARNING: Unable to verify checksum for C:\PROGRA~1\sina\UC\ActiveX\BROWSE~1.DLL
*** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\PROGRA~1\sina\UC\ActiveX\BROWSE~1.DLL –
BROWSE_1!DllUnregisterServer+0x662c:
02b97c76 f3a5 rep movsd ds:02849ada=41414141 es:00130000=78746341
0:000> g
(534.674): C++ EH exception – code e06d7363 (first chance)
(534.674): Access violation – code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000000 ebx=00000000 ecx=41414141 edx=77f79bb8 esi=00000000 edi=00000000
eip=41414141 esp=0012c8b8 ebp=0012c8d8 iopl=0 nv up ei pl zr na po nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
41414141 ?? ???

存在问题的代码：
ext:100076A2 add dword ptr [esi+4], 2
.text:100076A6 mov eax, [esi+4]
.text:100076A9 movzx ecx, word ptr [ebp-14h]
.text:100076AD push ecx ; size_t
.text:100076AE push dword ptr [ebp+8] ; void *
.text:100076B1 mov ecx, [esi+8]
.text:100076B4 add ecx, eax
.text:100076B6 push ecx ; void *
.text:100076B7 call _memcpy

|
|
v

.text:10007C30 LeadUp1: ; DATA XREF: .text:10007C24o
.text:10007C30 and edx, ecx
.text:10007C32 mov al, [esi]
.text:10007C34 mov [edi], al
.text:10007C36 mov al, [esi+1]
.text:10007C39 mov [edi+1], al
.text:10007C3C mov al, [esi+2]
.text:10007C3F shr ecx, 2
.text:10007C42 mov [edi+2], al
.text:10007C45 add esi, 3
.text:10007C48 add edi, 3
.text:10007C4B cmp ecx, 8
.text:10007C4E jb short loc_10007C1C
.text:10007C50 rep movsd
.text:10007C52 jmp ds:off_10007D08[edx*4]
.text:10007C52 ; ———————————————————————-
.text:10007C59 align 4
.text:10007C5C
.text:10007C5C LeadUp2: ; DATA XREF: .text:10007C28o
.text:10007C5C and edx, ecx
.text:10007C5E mov al, [esi]
.text:10007C60 mov [edi], al
.text:10007C62 mov al, [esi+1]
.text:10007C65 shr ecx, 2
.text:10007C68 mov [edi+1], al
.text:10007C6B add esi, 2
.text:10007C6E add edi, 2
.text:10007C71 cmp ecx, 8
.text:10007C74 jb short loc_10007C1C
.text:10007C76 rep movsd ————-Exception here.

2. clsid:77AE4780-75E0-4CB0-A162-D1BBE3D50384
C:\Program Files\sina\UC\ActiveX\BROWSER2UC.dll

Sub SendDownLoadFile (
ByVal astrDownDir As String
)

当astrDownDir参数设置为超常字符串时，发生栈溢出

调试信息：
(57c.1ac): Access violation – code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=41414140 ebx=00000000 ecx=41414140 edx=00000000 esi=0012d974 edi=77dbe2d0
eip=7800268d esp=0012d55c ebp=0012d580 iopl=0 nv up ei pl zr na po nc
cs=001b ss=0023 ds=0023 es=0023 fs=0038 gs=0000 efl=00000246
*** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\WINDOWS\system32\RPCRT4.dll –
RPCRT4!NDRCContextBinding+0x13:
7800268d 81780498badcfe cmp dword ptr [eax+0x4],0xfedcba98 ds:0023:41414144=????????
0:000> g
(57c.1ac): Unknown exception – code 00000006 (first chance)
(57c.1ac): Access violation – code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000000 ebx=02e9e510 ecx=78079582 edx=00000000 esi=0019535c edi=00000000
eip=41414141 esp=0012dba0 ebp=41414141 iopl=0 nv up ei pl zr na po nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
41414141 ?? ???

3. …………

解决方法：
在厂商没有推出相应的补丁之前，暂时停止使用。

厂商回应：
2007.01.08 发邮件给[email protected]
2007.01.08 新浪不甩我。再发送了一封邮件
2007.01.09 到目前为止，没收到任何回应。发布此公告