January 2005

ID: 00016
Ref: 16/2005
Date: 10 January 2005:15:38:46
Version: 1

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Title: SECUNIA ADVISORY ID: SA12889 - Microsoft Internet Explorer Multiple Vulnerabilities
Abstract: Some vulnerabilities have been discovered in Internet Explorer, which can be exploited by malicious people to compromise a user's system, conduct cross-site/zone scripting and bypass a security feature in Microsoft Windows XP SP2.
Vendors affected: Secunia
Operating systems affected: Secunia
Applications affected: Secunia

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Title
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SECUNIA ADVISORY ID: SA12889 - Microsoft Internet Explorer Multiple
Vulnerabilities

Detail
======

Some vulnerabilities have been discovered in Internet Explorer, which
can be exploited by malicious people to compromise a user's system,
conduct cross-site/zone scripting and bypass a security feature in
Microsoft Windows XP SP2.


TITLE:
Microsoft Internet Explorer Multiple Vulnerabilities

SECUNIA ADVISORY ID:
SA12889

VERIFY ADVISORY:
http://secunia.com/advisories/12889/

CRITICAL:
Extremely critical

IMPACT:
Security Bypass, Cross Site Scripting, System access

WHERE:
- From remote

REVISION:
5.0 originally posted 2004-10-20

SOFTWARE:
Microsoft Internet Explorer 6
http://secunia.com/product/11/

DESCRIPTION:
Some vulnerabilities have been discovered in Internet Explorer, which
can be exploited by malicious people to compromise a user's system,
conduct cross-site/zone scripting and bypass a security feature in
Microsoft Windows XP SP2.

1) Insufficient validation of drag and drop events from the "Internet"
zone to local resources for valid images or media files with embedded
HTML code. This can be exploited by e.g. a malicious web site to plant
arbitrary HTML documents on a user's system, which may allow execution
of arbitrary script code in the "Local Computer" zone.

This vulnerability is a variant of:
SA12321

NOTE: Microsoft Windows XP SP2 does not allow Active Scripting in
the "Local Computer" zone.

2) A security site / zone restriction error, where an embedded HTML
Help control on e.g. a malicious web site references a specially crafted
index (.hhk) file, can execute local HTML documents or inject arbitrary
script code in context of a previous loaded document using a malicious
javascript URI handler.

Successful exploitation may allow execution of arbitrary HTML and script
code in a user's browser session in context of arbitrary sites, or execution
of local programs with parameters from the "Local Computer" zone using a
HTML Help shortcut.

NOTE: This will bypass the "Local Computer" zone lockdown security feature
in SP2.

3) A security site / zone restriction error in the handling of the
"Related Topics" command in an embedded HTML Help control can be exploited
by e.g. a malicious website to execute arbitrary script code in the context
of arbitrary sites or zones.

NOTE: This may be exploited to bypass the "Local Computer" zone lockdown
security feature in SP2.

Secunia has constructed a test, which can be used to check if your browser
is affected by this issue:
http://secunia.com/internet_explorer_command_execution_vulnerability_test/

Vulnerability 1 and 2, or 3 alone, in combination with an inappropriate
behaviour where the ActiveX Data Object (ADO) model can write arbitrary
files can be exploited to compromise a user's system. This has been
confirmed on a fully patched system with Internet Explorer 6.0 and
Microsoft Windows XP SP2.

SOLUTION:
Use another product.

Alternative workarounds:
1) The vendor recommends that the "Drag and drop or copy and paste files"
option is disabled. 2, 3) Set security level to high for the "Internet" zone.

PROVIDED AND/OR DISCOVERED BY:
1) Discovered independently by:
* http-equiv
* Andreas Sandblad of Secunia Research (reported to Microsoft on 2004-10-13).

2) Discovered by:
* http-equiv

Additional information provided by:
* Roozbeh Afrasiabi

3) Discovered by:
* Paul, Greyhats Security
* Michael Evanchik

Additional information provided by:
* ShredderSub7

CHANGELOG:
2004-10-21: Updated advisory.
2004-10-28: Added another workaround in "Solution" section and linked to
Microsoft Knowledge Base article.
2004-11-02: Updated with additional information in "Description" and
"Solution" section.
2004-11-29: Updated "Description" section with additional information
from Paul.
2004-12-23: Added link to US-CERT vulnerability note.
2004-12-25: Updated "Description" section with additional information
from Paul and Michael Evanchik.
2005-01-07: Increased rating. Added link to test. Updated "Description"
and "Solution" sections.

ORIGINAL ADVISORY:
3) http://freehost07.websamba.com/greyhats/sp2rc-analysis.htm

OTHER REFERENCES:
SA12321:
http://secunia.com/advisories/12321/

How to Disable "Drag and Drop or copy and paste files" option in Internet
Explorer: http://support.microsoft.com/kb/888534

How to Disable Active Content in Internet Explorer:
http://support.microsoft.com/default.aspx?scid=kb;en-us;q154036

US-CERT VU#939688:
http://www.kb.cert.org/vuls/id/939688