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Luigi Auriemma
Application: EViews
http://www.eviews.com
Versions: <= 7.0.0.1 (aka 7.2)
Platforms: Windows
Bugs: A] memory corruption
B] heap overflow
Exploitation: remote
Date: 19 Sep 2011
Author: Luigi Auriemma
e-mail: aluigi@autistici.org
web: aluigi.org
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1) Introduction
2) Bugs
3) The Code
4) Fix
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1) Introduction
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EViews is a software for econometric and statistical analysis.
From vendor's website:
"Estimation, forecasting, statistical analysis, graphics, simulation,
data management, all in a powerful, graphical object-oriented
interface."
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2) Bugs
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A] memory corruption
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The program uses a particular function for allocating memory for the
arrays used in the WF1 files.
In short if the reallocation fails it's possible to write a memory
pointer and a NULL in the expected last two positions of the
"supposedly" reallocated array so with possibilities of corrupting
memory zones almost arbitrarialy:
00B1A2B0 /$ 56 PUSH ESI ; value + 0x32
00B1A2B1 |. 57 PUSH EDI
00B1A2B2 |. 8B7C24 0C MOV EDI,DWORD PTR SS:[ESP+C]
00B1A2B6 |. 8BF1 MOV ESI,ECX
00B1A2B8 |. 56 PUSH ESI
00B1A2B9 |. 8D04BD 00000000 LEA EAX,DWORD PTR DS:[EDI*4] ; value * 4 (unexploitable)
00B1A2C0 |. 50 PUSH EAX
00B1A2C1 |. B9 38F8E600 MOV ECX,EViews7.00E6F838
00B1A2C6 |. E8 4527F7FF CALL EViews7.00A8CA10 ; allocation
...
00A8BB41 |. 897C39 FC MOV DWORD PTR DS:[ECX+EDI-4],EDI ; write4
00A8BB45 |. C70439 00000000 MOV DWORD PTR DS:[ECX+EDI],0 ; write4
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B] heap overflow
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Heap overflow/corruption (no additional analysis) during the handling
of the PRG files:
00B90BF4 |. 8B1496 MOV EDX,DWORD PTR DS:[ESI+EDX*4]
00B90BF7 |. EB 07 JMP SHORT EViews7.00B90C00 ; EDX is controlled
00B90BF9 |> 397A 04 /CMP DWORD PTR DS:[EDX+4],EDI ; EDI is usually zero
00B90BFC |. 74 0E |JE SHORT EViews7.00B90C0C
00B90BFE |. 8B12 |MOV EDX,DWORD PTR DS:[EDX]
00B90C00 |> 85D2 TEST EDX,EDX
00B90C02 |.^75 F5 \JNZ SHORT EViews7.00B90BF9
00B90C04 |. 33C0 XOR EAX,EAX
00B90C06 |> 5F POP EDI
00B90C07 |> 5E POP ESI
00B90C08 |. 5D POP EBP
00B90C09 |. C2 0400 RETN 4
00B90C0C |> 8B42 08 MOV EAX,DWORD PTR DS:[EDX+8] ; get the new value
00B90C0F \.^EB F5 JMP SHORT EViews7.00B90C06
...
00B295D8 |. E8 EF750600 CALL EViews7.00B90BCC ; the above function
00B295DD |. 85C0 TEST EAX,EAX
00B295DF |. 74 14 JE SHORT EViews7.00B295F5
00B295E1 |. 8378 4C 00 CMP DWORD PTR DS:[EAX+4C],0
00B295E5 |. 74 0E JE SHORT EViews7.00B295F5
00B295E7 |. 8B48 4C MOV ECX,DWORD PTR DS:[EAX+4C]
00B295EA |. 8B01 MOV EAX,DWORD PTR DS:[ECX]
00B295EC |. 6A 00 PUSH 0
00B295EE |. 56 PUSH ESI
00B295EF |. FF90 9C000000 CALL DWORD PTR DS:[EAX+9C] ; code execution
The only "obstacle" to the exploitation could be EDI handled at address
00B54CE5 because sometimes it's zero and other times it isn't but my
proof-of-concept and analysis is absolutely far from being optimized so
I there are for sure ways to control it better and bypassing the
comparison.
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3) The Code
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http://aluigi.org/poc/eviews_1.zip
http://www.exploit-db.com/sploits/17878.zip
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4) Fix
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No fix.
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