-----BEGIN PGP SIGNED MESSAGE----- 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: #7d6d2db4 =================== Following HTML code forces MS IE 6 to crash: >

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 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/ -----BEGIN PGP SIGNATURE----- Version: n/a Comment: http://morph3us.org/ iD8DBQFEdjPVkCo6/ctnOpYRAyHUAKCEVV7FWNe+R+n1LcnXBdJqLvPbPwCdEhsf xDEUBcvk88NUT5rLt8Vl0VU= =4DXQ -----END PGP SIGNATURE-----