Microsoft PowerPoint Malformed Record Memory Corruption Vulnerability


By Sowhat of Nevis Labs
2006.08.08

http://www.nevisnetworks.com 
http://secway.org/advisory/AD20060808.txt 



Vendor
Microsoft Inc.

Microsoft PowerPoint 2000
Microsoft PowerPoint 2002
Microsoft Office PowerPoint 2003
PowerPoint 2004 for Mac
PowerPoint 2004 v. X for Mac


Remote: YES
Exploitable: maybe ;)

CVE: CVE-2006-3449



Overview:

This vulnerability allows remote attackers to execute arbitrary code in
the context of the logged in user. An array boundary condition may be
violated by a malicious .PPT file in order to redirect execution into
attacker-supplied data. Exploitation requires that the attacker coerce or
persuade the victim to open a malicious .PPT file.


Details:

The specific flaw exists within the parsing of the BIFF(?) file format used
by Microsoft PowerPoint.


There will be a memory corruption during the analysis of a malformed PPT Record.


The disassembly code:


3009a818 3945fc           cmp     [ebp-0x4],eax
3009a81b 7703             ja      POWERPNT+0x9a820 (3009a820)
3009a81d 8b45fc           mov     eax,[ebp-0x4]
3009a820 8b7308           mov     esi,[ebx+0x8]
3009a823 8b7d08           mov     edi,[ebp+0x8]
3009a826 2945fc           sub     [ebp-0x4],eax
3009a829 014508           add     [ebp+0x8],eax
3009a82c 8bc8             mov     ecx,eax
3009a82e 8bd1             mov     edx,ecx
3009a830 c1e902           shr     ecx,0x2
3009a833 f3a5             rep     movsd						----> Access violation here. :)
3009a835 8bca             mov     ecx,edx
3009a837 83e103           and     ecx,0x3
3009a83a f3a4             rep     movsb
3009a83c 014308           add     [ebx+0x8],eax
3009a83f 014318           add     [ebx+0x18],eax
3009a842 837dfc00         cmp     dword ptr [ebp-0x4],0x0
3009a846 75b7             jnz     POWERPNT+0x9a7ff (3009a7ff)
3009a848 8b450c           mov     eax,[ebp+0xc]
3009a84b 5f               pop     edi
3009a84c 5e               pop     esi
3009a84d 5b               pop     ebx
3009a84e c9               leave
3009a84f c20800           ret     0x8


Code execution may possible.


POC:

No POC will be supplied


Fix:

Microsoft has released an update for Microsoft Office which is
set to address this issue. This can be downloaded from:

http://www.microsoft.com/technet/security/bulletin/MS06-048.mspx 


Vendor Response:

2006.07.14 Vendor notified via secure@microsoft.com 
2006.07.15 Vendor responded
2006.08.08 Vendor released MS06-048 patch
2006.08.08 Advisory released


Common Vulnerabilities and Exposures (CVE) Information:

The Common Vulnerabilities and Exposures (CVE) project has assigned
the following names to these issues.  These are candidates for
inclusion in the CVE list (http://cve.mitre.org), which standardizes 
names for security problems.


        CVE-2006-3449




Greetings to Becky PhD. ;)


Reference:

1. http://www.microsoft.com/technet/security/Bulletin/MS06-048.mspx 
2. http://secway.org/vuln.htm 



-- 
Sowhat
http://secway.org 
"Life is like a bug, Do you know how to exploit it ?"