Microsoft Internet Explorer 'javaprxy.dll' COM Object Exception Handling Lets Remote Users Execute Arbitrary Code
SecurityTracker Alert ID: 1014329|
SecurityTracker URL: http://securitytracker.com/id/1014329
(Links to External Site)
Updated: Jun 24 2008|
Original Entry Date: Jun 29 2005
Denial of service via network, Execution of arbitrary code via network, User access via network|
Exploit Included: Yes |
Version(s): 6.0 SP1 and prior versions; Tested on 6.0.2900.2180|
A vulnerability was reported in Microsoft Internet Explorer in 'javaprxy.dll'. A remote user can cause the target user's browser to crash or execute arbitrary code.|
A remote user can create specially crafted HTML that, when loaded by the target user, will trigger a heap overflow in 'javaprxy.dll' and cause the target user's browser to crash. Specially crafted object tags can cause certain COM componenets to crash.
It is also possible to overwrite a function pointer to execute arbitrary code.
A demonstration exploit from FrSIRT is available at:
The vendor was notified on June 17, 2005.
sk0L and Martin Eiszner from SEC-CONSULT discovered this vulnerability.
A remote user can cause the target user's browser to crash.|
A remote user can execute arbitrary code on the target system.
No solution was available at the time of this entry.|
Microsoft has described some workarounds at:
Vendor URL: www.microsoft.com/ (Links to External Site)
Exception handling error|
|Underlying OS: Windows (Any)|
This archive entry has one or more follow-up message(s) listed below.|
Source Message Contents
Subject: [Full-disclosure] SEC-CONSULT SA-20050629-0|
SEC-CONSULT Security Advisory < 20050629-0 >
title: IE6 javaprxy.dll COM instantiation heap corruption
program: Internet Explorer
vulnerable version: 6.0.2900.2180
by: sk0L & Martin Eiszner / SEC-CONSULT /
Internet Explorer supports instantiation of non-ActiveX controls, e.g
COM objects, via <object> tags. according to M$, COM components respond
gracefully to attempts to treat them as non-ActiveX controls. on the
contrary, we found that at least 20 of the objects available on an
average XP system either lead to an instant crash or an exception after
a few reloads.
Loading HTML documents with certain embedded CLSIDs results in
null-pointer exceptions or memory corruption. in one case, we could
leverage this bug to overwrite a function pointer in the data segment.
it *may* be possible to exploit this issue to execute arbitrary code in
the context of IE.
proof of concept:
this simple CGI should crash IE.
# in order for this to work javaprxy.dll must be available on the client.
my $clsid = '03D9F3F2-B0E3-11D2-B081-006008039BF0'; # javaprxy.dll
my $html1 = "<html><body>\n<object
my $html2 = "\n</body><script>location.reload();</script></html>\n";
print "Content-Type: text/html;\r\n\r\n";
on our lab machine, we, end up with eax=00410041, and an exception
occurs at the following location in javaprxy.dll:
.text:7C508660 mov eax, [ecx]
.text:7C508662 test eax, eax
.text:7C508664 jz short locret_7C50866C
.text:7C508666 mov ecx, [eax]
.text:7C508668 push eax
.text:7C508669 call dword ptr [ecx+8]
as you can see, this situation may be exploitable, considering that we
have some level of control over eax.
internet explorer 6.0.2900.2180.xpsp_sp2_gdr.050301-1519
these are the versions tested, other versions may of course be vulnerable.
vendor notified: 2005-06-17
vendor response: 2005-06-17
patch available: ?
microsoft does not confirm the vulnerability, as their product team can
not reproduce condition. however, they are looking at making changes to
handle COM objects in a more robust manner in the future.
SGT ::: walter|bruder, flo, tke, dfa :::
Full-Disclosure - We believe in it.
Hosted and sponsored by Secunia - http://secunia.com/