[NT] Cumulative Security Update for Internet Explorer (MS06-013)



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Cumulative Security Update for Internet Explorer (MS06-013)
------------------------------------------------------------------------


SUMMARY

Multiple remote code execution, information disclosure and Spoofing in
Microsoft Internet Explorer allow attackers to execute arbitrary code,
retrieve information and spoof the user UI.

DETAILS

Vulnerable Systems:
* Microsoft Windows 2000 Service Pack 4
* Microsoft Windows XP Service Pack 1 and Microsoft Windows XP Service
Pack 2
* Microsoft Windows XP Professional x64 Edition
* Microsoft Windows Server 2003 and Microsoft Windows Server 2003 Service
Pack 1
* Microsoft Windows Server 2003 for Itanium-based Systems and Microsoft
Windows Server 2003 with Service Pack 1 for Itanium-based Systems
* Microsoft Windows Server 2003 x64 Edition family
* Microsoft Windows 98, Microsoft Windows 98 Second Edition (SE), and
Microsoft Windows Millennium Edition (ME) Review the FAQ section of this
bulletin for details about these operating systems.

Note The security updates for Microsoft Windows Server 2003, Microsoft
Windows Server 2003 Service Pack 1, and Microsoft Windows Server 2003 x64
Edition also apply to Microsoft Windows Server 2003 R2.

* Internet Explorer 5.01 Service Pack 4 on Microsoft Windows 2000 Service
Pack 4
<http://www.microsoft.com/downloads/details.aspx?FamilyId=594E7B87-AF8F-4346-9164-596E3E5C22B1> Download the update
* Internet Explorer 6 Service Pack 1 on Microsoft Windows 2000 Service
Pack 4 or on Microsoft Windows XP Service Pack 1
<http://www.microsoft.com/downloads/details.aspx?FamilyId=033C41E1-2B36-4696-987A-099FC57E0129> Download the update
* Internet Explorer 6 for Microsoft Windows XP Service Pack 2
<http://www.microsoft.com/downloads/details.aspx?FamilyId=F05FFB31-E6B4-4771-81F1-4ACCEBF72133> Download the update
* Internet Explorer 6 for Microsoft Windows Server 2003 and Microsoft
Windows Server 2003 Service Pack 1
<http://www.microsoft.com/downloads/details.aspx?FamilyId=EE566871-D217-41D3-BECC-B27FAFA00054> Download the update
* Internet Explorer 6 for Microsoft Windows Server 2003 for Itanium-based
Systems and Microsoft Windows Server 2003 with SP1 for Itanium-based
Systems
<http://www.microsoft.com/downloads/details.aspx?FamilyId=E584957C-0ABE-4129-ABAF-AA2852AD62A3> Download the update
* Internet Explorer 6 for Microsoft Windows Server 2003 x64 Edition
<http://www.microsoft.com/downloads/details.aspx?FamilyId=5A1C8BE3-39EE-4937-9BD1-280FC35125C6> Download the update
* Internet Explorer 6 for Microsoft Windows XP Professional x64 Edition

<http://www.microsoft.com/downloads/details.aspx?FamilyId=C278FE3E-620A-4BBC-868B-CA2D9EFF7AC3> Download the update
* Internet Explorer 6 Service Pack 1 on Microsoft Windows 98, on
Microsoft Windows 98 SE, or on Microsoft Windows Millennium Edition
Review the FAQ section of this bulletin for details about this version.


DHTML Method Call Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1359>
CVE-2006-1359:
A remote code execution vulnerability exists in the way Internet Explorer
displays a Web page that contains certain unexpected method calls to HTML
objects. As a result, system memory may be corrupted in such a way that an
attacker could execute arbitrary code if a user visited a malicious Web
site. An attacker who successfully exploited this vulnerability could take
complete control of an affected system.

Mitigating Factors for DHTML Method Call Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1359>
CVE-2006-1359:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability in the e-mail vector because reading e-mail messages in plain text is the default configuration for Outlook Express. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

Workarounds for DHTML Method Call Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1359>
CVE-2006-1359:
Microsoft has tested the following workarounds. While these workarounds
will not correct the underlying vulnerability, they help block known
attack vectors. When a workaround reduces functionality, it is identified
in the following section.

* Configure Internet Explorer to prompt before running Active Scripting
or to disable Active Scripting in the Internet and Local intranet security
zone

You can help protect against this vulnerability by changing your settings
to prompt before running Active Scripting or to disable Active Scripting
in the Internet and Local intranet security zone. To do this, follow these
steps:

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
7. Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet
security zones may cause some Web sites to work incorrectly. If you have
difficulty using a Web site after you change this setting, and you are
sure the site is safe to use, you can add that site to your list of
trusted sites. This will allow the site to work correctly.

Impact of Workaround: There are side effects to prompting before running
Active Scripting. Many Web sites that are on the Internet or on an
intranet use Active Scripting to provide additional functionality. For
example, an online e-commerce site or banking site may use Active
Scripting to provide menus, ordering forms, or even account statements.
Prompting before running Active Scripting is a global setting that affects
all Internet and intranet sites. You will be prompted frequently when you
enable this workaround. For each prompt, if you feel you trust the site
that you are visiting, click Yes to run Active Scripting. If you do not
want to be prompted for all these sites, use the steps outlined in "Add
sites that you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Set Internet and Local intranet security zone settings to High to prompt
before running ActiveX Controls and Active Scripting in these zones

You can help protect against this vulnerability by changing your settings
for the Internet security zone to prompt before running ActiveX controls
and Active Scripting. You can do this by setting your browser security to
High.

To raise the browsing security level in Microsoft Internet Explorer,
follow these steps:

1. On the Internet Explorer Tools menu, click Internet Options.
2. In the Internet Options dialog box, click the Security tab, and then
click the Internet icon.
3. Under Security level for this zone, move the slider to High. This sets
the security level for all Web sites you visit to High.

Note If no slider is visible, click Default Level, and then move the
slider to High.

Note Setting the level to High may cause some Web sites to work
incorrectly. If you have difficulty using a Web site after you change this
setting, and you are sure the site is safe to use, you can add that site
to your list of trusted sites. This will allow the site to work correctly
even with the security setting set to High.

Impact of Workaround: There are side effects to prompting before running
ActiveX Controls and Active Scripting. Many Web sites that are on the
Internet or on an intranet use ActiveX or Active Scripting to provide
additional functionality. For example, an online e-commerce site or
banking site may use ActiveX Controls to provide menus, ordering forms, or
even account statements. Prompting before running ActiveX Controls or
Active Scripting is a global setting that affects all Internet and
intranet sites. You will be prompted frequently when you enable this
workaround. For each prompt, if you feel you trust the site that you are
visiting, click Yes to run ActiveX Controls or Active Scripting. If you do
not want to be prompted for all these sites, use the steps outlined in
"Add sites that you trust to Internet Explorer's Trusted sites zone

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

<Note> Note Add any sites that you trust not to take malicious action on
your computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

FAQ for DHTML Method Call Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1359>
CVE-2006-1359:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
When Internet Explorer displays a Web page that contains certain
unexpected method calls to HTML objects, system memory may be corrupted in
such a way that an attacker could execute arbitrary code.

Specifically, the public postings discuss a potential behavior in Internet
Explorer in the way that HTML objects may handle an unexpected
createTextRange() method call to an HTML object. A Web page that is
specially crafted to exploit this vulnerability will cause Internet
Explorer to fail. As a result of this, system memory may be corrupted in
such a way that an attacker could execute arbitrary code.

What is the createTextRange() method?
The createTextRange() method is a dynamic HTML (DHTML) method that is
exposed by the DHTML Object Model. For more information about DHTML
methods, visit the
<http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/reference/methods.asp> MSDN Library Web site.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

Could this vulnerability be exploited through e-mail?
This vulnerability could not be exploited automatically through e-mail or
while viewing e-mail messages in the preview pane while using Outlook or
Outlook Express. Customers would have to click on a link that would take
them to a malicious Web site, or open an attachment that could exploit the
vulnerability.

What systems are primarily at risk from the vulnerability?
This vulnerability requires a user to be logged on and visiting a Web site
for any malicious action to occur. Therefore, any systems where Internet
Explorer is used frequently, such as workstations or terminal servers, are
at the most risk from this vulnerability.

Are Windows 98, Windows 98 Second Edition or Windows Millennium Edition
critically affected by this vulnerability?
Yes. Windows 98, Windows 98 Second Edition, and Windows Millennium Edition
are critically affected by this vulnerability. The security updates are
available from the <http://go.microsoft.com/fwlink/?LinkId=21130> Windows
Update Web site. For more information about severity ratings, visit the
following <http://go.microsoft.com/fwlink/?LinkId=21140> Web site.

What does the update do?
The update removes the vulnerability by changing the way that Internet
Explorer initializes memory before using it.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
Yes. This vulnerability has been publicly disclosed. It has been assigned
Common Vulnerability and Exposure number CVE-2006-1359.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
Yes. When the security bulletin was released, Microsoft had received
information that this vulnerability was being exploited.

Does applying this security update help protect customers from the code
that has been published publicly that attempts to exploit this
vulnerability?
Yes. This security update addresses the vulnerability that is currently
being exploited. The vulnerability that has been addressed has been
assigned the Common Vulnerability and Exposure number CVE-2006-1359.

Multiple Event Handler Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1245>
CVE-2006-1245:
A remote code execution vulnerability exists in the way Internet Explorer
handles multiple event handlers in an HTML element. An attacker could
exploit the vulnerability by constructing a malicious Web page that could
potentially allow remote code execution if a user visited the malicious
Web site. An attacker who successfully exploited this vulnerability could
take complete control of an affected system.

Mitigating Factors for Multiple Event Handler Memory Corruption
Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1245>
CVE-2006-1245:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability in the e-mail vector because reading e-mail messages in plain text is the default configuration for Outlook Express. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

Workarounds for Multiple Event Handler Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1245>
CVE-2006-1245:
No workarounds have been identified for this vulnerability.

FAQ for Multiple Event Handler Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1245>
CVE-2006-1245:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
When Internet Explorer handles multiple event handlers in an HTML element,
system memory may be corrupted in such a way that an attacker could
execute arbitrary code.

For example, when Internet Explorer displays a Web page that contains
multiple onLoad events in an HTML element, system memory may be corrupted
in such a way that an attacker could execute arbitrary code.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user is logged on and reading HTML
e-mail messages or that a user is logged on and visits a Web site for any
malicious action to occur. Therefore, any systems where HTML e-mail
messages are read or where Internet Explorer is used frequently, such as
workstations or terminal servers, are at the most risk from this
vulnerability.

Note The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario. It may be possible to exploit this
vulnerability without making use of Active Scripting. However, our
investigation has shown that this is harder to exploit without the use of
Active Scripting.

Are Windows 98, Windows 98 Second Edition or Windows Millennium Edition
critically affected by this vulnerability?
Yes. Windows 98, Windows 98 Second Edition, and Windows Millennium Edition
are critically affected by this vulnerability. The security updates are
available from the <http://go.microsoft.com/fwlink/?LinkId=21130> Windows
Update Web site. For more information about severity ratings, visit the
following <http://go.microsoft.com/fwlink/?LinkId=21140> Web site.

What does the update do?
The update removes the vulnerability by modifying the way that Internet
Explorer handles multiple event handlers so that Internet Explorer does
not exit in an exploitable way.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
Yes. This vulnerability has been publicly disclosed. It has been assigned
Common Vulnerability and Exposure number CVE-2006-1245.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had seen examples of proof of concept code published
publicly but had not received any information to indicate that this
vulnerability had been publicly used to attack customers when this
security bulletin was originally issued.

Does applying this security update help protect customers from the code
that has been published publicly that attempts to exploit this
vulnerability?
Yes. This security update addresses the vulnerability that potentially
could be exploited by using the published proof of concept code. The
vulnerability that has been addressed has been assigned the Common
Vulnerability and Exposure number CVE-2006-1245.

HTA Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1388>
CVE-2006-1388:
A remote code execution vulnerability exists in Internet Explorer. An HTML
Application (HTA) can be initiated in a way that bypasses the security
control within Internet Explorer. This allows an HTA to execute without
Internet Explorer displaying the normal security dialog box. An attacker
could exploit the vulnerability by constructing a malicious Web page that
could potentially allow remote code execution if a user visited the
malicious Web site. An attacker who successfully exploited this
vulnerability could take complete control of an affected system.

Mitigating Factors for HTA Execution Vulnerability - CVE-2006-1388:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

Workarounds for HTA Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1388>
CVE-2006-1388:
Microsoft has tested the following workarounds. While these workarounds
will not correct the underlying vulnerability, they help block known
attack vectors. When a workaround reduces functionality, it is identified
in the following section.

* Un-register the Mshta.exe file

To un-register the Mshta.exe file, use the following command:

Click Start, click Run, type ""%windir%\system32\mshta.exe /unregister"
(without the quotation marks), and then click OK.

Impact of Workaround: Users will be prompted to select a software to open
HTML Applications (.HTA files) with.

To undo this change, re-register Mshta.exe by following the above steps.
Replace the text in Step 1 with ""%windir%\system32\mshta.exe /register"
(without the quotation marks).

* Modify the Access Control List on the Mshta.exe file

You can help protect against this vulnerability by modifying the Access
Control List on the Mshta.exe file. To do this, follow these steps:

1. Click Start, click Run, type "cmd" (without the quotation marks), and
then click OK.
2. Type the following command at a command prompt. Make a note of the
current ACLs that are on the file (including inheritance settings) for
future reference to undo this modification:
cacls %windir%\system32\mshta.exe
3. Type the following command at a command prompt to deny the everyone
group access to this file:
cacls %windir%\system32\mshta.exe /d everyone

Impact of Workaround: HTML Applications (.HTA files) will stop working.

* Configure Internet Explorer to prompt before running Active Scripting
or disable Active Scripting in the Internet and Local intranet security
zone

You can help protect against this vulnerability by changing your settings
to prompt before running Active Scripting or to disable Active Scripting
in the Internet and Local intranet security zone. To do this, follow these
steps:

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
7. Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet
security zones may cause some Web sites to work incorrectly. If you have
difficulty using a Web site after you change this setting, and you are
sure the site is safe to use, you can add that site to your list of
trusted sites. This will allow the site to work correctly.

Impact of Workaround: There are side effects to prompting before running
Active Scripting. Many Web sites that are on the Internet or on an
intranet use Active Scripting to provide additional functionality. For
example, an online e-commerce site or banking site may use Active
Scripting to provide menus, ordering forms, or even account statements.
Prompting before running Active Scripting is a global setting that affects
all Internet and intranet sites. You will be prompted frequently when you
enable this workaround. For each prompt, if you feel you trust the site
that you are visiting, click Yes to run Active Scripting. If you do not
want to be prompted for all these sites, use the steps outlined in "Add
sites that you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Set Internet and Local intranet security zone settings to High to prompt
before running ActiveX Controls and Active Scripting in these zones

You can help protect against this vulnerability by changing your settings
for the Internet security zone to prompt before running ActiveX controls.
You can do this by setting your browser security to High.

To raise the browsing security level in Microsoft Internet Explorer,
follow these steps:

1. On the Internet Explorer Tools menu, click Internet Options.
2. In the Internet Options dialog box, click the Security tab, and then
click the Internet icon.
3. Under Security level for this zone, move the slider to High. This sets
the security level for all Web sites you visit to High.

Note If no slider is visible, click Default Level, and then move the
slider to High.

Note Setting the level to High may cause some Web sites to work
incorrectly. If you have difficulty using a Web site after you change this
setting, and you are sure the site is safe to use, you can add that site
to your list of trusted sites. This will allow the site to work correctly
even with the security setting set to High.

Impact of Workaround: There are side effects to prompting before running
ActiveX Controls and Active Scripting. Many Web sites that are on the
Internet or on an intranet use ActiveX or Active Scripting to provide
additional functionality. For example, an online e-commerce site or
banking site may use ActiveX Controls to provide menus, ordering forms, or
even account statements. Prompting before running ActiveX Controls or
Active Scripting is a global setting that affects all Internet and
intranet sites. You will be prompted frequently when you enable this
workaround. For each prompt, if you feel you trust the site that you are
visiting, click Yes to run ActiveX Controls or Active Scripting. If you do
not want to be prompted for all these sites, use the steps outlined in
"Add sites that you trust to Internet Explorer's Trusted sites zone

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

FAQ for HTA Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1388>
CVE-2006-1388:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
An HTML Application (HTA) can be initiated in a way that bypasses the
security control within Internet Explorer. This allows an HTA to execute
without Internet Explorer displaying the normal security dialog box.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires a user to be logged on and visiting a Web site
for any malicious action to occur. Therefore, any systems where Internet
Explorer is used frequently, such as workstations or terminal servers, are
at the most risk from this vulnerability.

Are Windows 98, Windows 98 Second Edition or Windows Millennium Edition
critically affected by this vulnerability?
Yes. Windows 98, Windows 98 Second Edition, and Windows Millennium Edition
are critically affected by this vulnerability. The security updates are
available from the <http://go.microsoft.com/fwlink/?LinkId=21130> Windows
Update Web site. For more information about severity ratings, visit the
following <http://go.microsoft.com/fwlink/?LinkId=21140> Web site.

What does the update do?
The update removes the vulnerability by changing Internet Explorer so that
the appropriate security dialog is displayed.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.

HTML Parsing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1185>
CVE-2006-1185:

A remote code execution vulnerability exists in the way Internet Explorer
handles specially crafted and not valid HTML. An attacker could exploit
the vulnerability by constructing a malicious Web page that could
potentially allow remote code execution if a user visited the malicious
Web site. An attacker who successfully exploited this vulnerability could
take complete control of an affected system.

Mitigating Factors for HTML Parsing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1185>
CVE-2006-1185:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability in the e-mail vector because reading e-mail messages in plain text is the default configuration for Outlook Express. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

* This vulnerability does not affect Internet Explorer 6 Service Pack 1
on Windows XP Service Pack 1, Windows 2000 Service Pack 4, Windows 98,
Windows 98 Second Edition (SE), or Windows Millennium Edition (ME).


Workarounds for HTML Parsing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1185>
CVE-2006-1185:
No workarounds have been identified for this vulnerability.

FAQ for HTML Parsing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1185>
CVE-2006-1185:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
When Internet Explorer handles specially crafted and not valid HTML it may
corrupt system memory in such a way that an attacker could execute
arbitrary code.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user is logged on and reading HTML
e-mail messages or that a user is logged on and visits a Web site for any
malicious action to occur. Therefore, any systems where HTML e-mail
messages are read or where Internet Explorer is used frequently, such as
workstations or terminal servers, are at the most risk from this
vulnerability.

What does the update do?
The update removes the vulnerability by modifying the way that Internet
Explorer handles the reported specially crafted and not valid HTML.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.

COM Object Instantiation Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1186>
CVE-2006-1186:
A remote code execution vulnerability exists in the way Internet Explorer
instantiates COM objects that are not intended to be instantiated in
Internet Explorer. An attacker could exploit the vulnerability by
constructing a malicious Web page that could potentially allow remote code
execution if a user visited the malicious Web site. An attacker who
successfully exploited this vulnerability could take complete control of
an affected system.

Mitigating Factors for COM Object Instantiation Memory Corruption
Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1186>
CVE-2006-1186:
* Customers who have installed the security update included with
Microsoft Security Bulletin
<http://go.microsoft.com/fwlink/?LinkId=50690> MS05-052 or a later
security bulletin for Internet Explorer are not at risk from attacks
originating from the Internet zone.

* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing ActiveX Controls from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability. See the FAQ section for this security update for more information about Internet Explorer Enhanced Security Configuration.

Workarounds for COM Object Instantiation Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1186>
CVE-2006-1186:
Microsoft has tested the following workarounds. While these workarounds
will not correct the underlying vulnerability, they help block known
attack vectors. When a workaround reduces functionality, it is identified
in the following section.

* Configure Internet Explorer to prompt before running ActiveX Controls
or disable ActiveX Controls in the Internet and Local intranet security
zone

You can help protect against this vulnerability by changing your Internet
Explorer settings to prompt before running ActiveX controls. To do this,
follow these steps:

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the ActiveX controls and plug-ins section, under
Run ActiveX controls and plug-ins, click Prompt or Disable, and then click
OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the ActiveX controls and plug-ins section, under
Run ActiveX controls and plug-ins, click Prompt or Disable, and then click
OK.
7. Click OK two times to return to Internet Explorer.

Impact of Workaround: There are side effects to prompting before running
ActiveX controls. Many Web sites that are on the Internet or on an
intranet use ActiveX to provide additional functionality. For example, an
online e-commerce site or banking site may use ActiveX controls to provide
menus, ordering forms, or even account statements. Prompting before
running ActiveX controls is a global setting that affects all Internet and
intranet sites. You will be prompted frequently when you enable this
workaround. For each prompt, if you feel you trust the site that you are
visiting, click Yes to run ActiveX controls. If you do not want to be
prompted for all these sites, use the steps outlined in "Add sites that
you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

<Note> Note Add any sites that you trust not to take malicious action on
your computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Set Internet and Local intranet security zone settings to High to prompt
before running ActiveX Controls and Active Scripting in these zones

You can help protect against this vulnerability by changing your settings
for the Internet security zone to prompt before running ActiveX controls.
You can do this by setting your browser security to High.

To raise the browsing security level in Microsoft Internet Explorer,
follow these steps:

1. On the Internet Explorer Tools menu, click Internet Options.
2. In the Internet Options dialog box, click the Security tab, and then
click the Internet icon.
3. Under Security level for this zone, move the slider to High. This sets
the security level for all Web sites you visit to High.

<Note> Note If no slider is visible, click Default Level, and then move
the slider to High.

<Note> Note Setting the level to High may cause some Web sites to work
incorrectly. If you have difficulty using a Web site after you change this
setting, and you are sure the site is safe to use, you can add that site
to your list of trusted sites. This will allow the site to work correctly
even with the security setting set to High.

<Impact of Workaround:> Impact of Workaround: There are side effects to
prompting before running ActiveX controls. Many Web sites that are on the
Internet or on an intranet use ActiveX to provide additional
functionality. For example, an online e-commerce site or banking site may
use ActiveX controls to provide menus, ordering forms, or even account
statements. Prompting before running ActiveX controls is a global setting
that affects all Internet and intranet sites. You will be prompted
frequently when you enable this workaround. For each prompt, if you feel
you trust the site that you are visiting, click Yes to run ActiveX
controls. If you do not want to be prompted for all these sites, use the
steps outlined in "Add sites that you trust to Internet Explorer's Trusted
sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

<Note> Note Add any sites that you trust not to take malicious action on
your computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Prevent COM objects from running in Internet Explorer

You can disable attempts to instantiate a COM object in Internet Explorer
by setting the kill bit for the control in the registry.

Warning If you use Registry Editor incorrectly, you may cause serious
problems that may require you to reinstall your operating system.
Microsoft cannot guarantee that you can solve problems that result from
using Registry Editor incorrectly. Use Registry Editor at your own risk.

For detailed steps that you can use to prevent a control from running in
Internet Explorer, see <http://support.microsoft.com/kb/240797> Microsoft
Knowledge Base Article 240797. Follow these steps in this article to
create a Compatibility Flags value in the registry to prevent a COM object
from being instantiated in Internet Explorer.

For example, to set the kill bit for a CLSID in the Mdt2gddr.dll, file
that is included in this security update, paste the following text in a
text editor such as Notepad. Then, save the file by using the .reg file
name extension.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX
Compatibility\{1F7DD4F2-CAC3-11D0-A35B-00AA00BDCDFD}]
"Compatibility Flags"=dword:00000400

You can apply this .reg file to individual systems by double-clicking it.
You can also apply it across domains by using Group Policy. For more
information about Group Policy, visit the following Microsoft Web sites:


<http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/TechRef/6d7cb788-b31d-4d17-9f1e-b5ddaa6deecd.mspx> Group Policy collection


<http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/TechRef/47ba1311-6cca-414f-98c9-2d7f99fca8a3.mspx> What is Group Policy Object Editor?


<http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/TechRef/e926577a-5619-4912-b5d9-e73d4bdc9491.mspx> Core Group Policy tools and settings

Note You must restart Internet Explorer for your changes to take effect.

Impact of Workaround: There is no impact as long as the COM object is not
intended to be used in Internet Explorer.

FAQ for COM Object Instantiation Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1186>
CVE-2006-1186:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
When Internet Explorer tries to instantiate certain COM objects as ActiveX
Controls, the COM objects may corrupt the system state in such a way that
an attacker could execute arbitrary code.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user is logged on and visits a Web site
for any malicious action to occur. Therefore, any systems where Internet
Explorer is used frequently, such as workstations or terminal servers, are
at the most risk from this vulnerability.

Note Customers who have installed the security update included with
Microsoft Security Bulletin
<http://go.microsoft.com/fwlink/?LinkId=50690> MS05-052 or a later
security bulletin for Internet Explorer are not at risk from attacks
originating from the Internet zone.

Are Windows 98, Windows 98 Second Edition or Windows Millennium Edition
critically affected by this vulnerability?
Yes. Windows 98, Windows 98 Second Edition, and Windows Millennium Edition
are critically affected by this vulnerability. The security updates are
available from the <http://go.microsoft.com/fwlink/?LinkId=21130> Windows
Update Web site. For more information about severity ratings, visit the
following <http://go.microsoft.com/fwlink/?LinkId=21140> Web site.

What does the update do?
Because not all COM objects are designed to be accessed through Internet
Explorer, this update sets the <http://support.microsoft.com/kb/240797>
kill bit for a list of Class Identifiers (CLSIDs) for COM objects that
have been found to exhibit similar behavior to the COM object
Instantiation Memory Corruption Vulnerability that is addressed in
<http://go.microsoft.com/fwlink/?LinkId=53511> Microsoft Security Bulletin
MS05-054. To help protect customers, this update prevents these CLSIDs
from being instantiated in Internet Explorer. For more information about
kill bits, see <http://support.microsoft.com/kb/240797> Microsoft
Knowledge Base Article 240797.

The Class Identifiers and corresponding COM objects are as follows.

1F7DD4F2-CAC3-11D0-A35B-00AA00BDCDFD Mdt2gddr.dll
1F7DD4F3-CAC3-11D0-A35B-00AA00BDCDFD Mdt2gddr.dll
B0406342-B0C5-11d0-89A9-00A0C9054129 Mdt2dd.dll
B0406343-B0C5-11d0-89A9-00A0C9054129 Mdt2dd.dll
D24D4450-1F01-11D1-8E63-006097D2DF48 Mdt2dd.dll
4CECCEB1-8359-11D0-A34E-00AA00BDCDFD Mdt2gddo.dll
4CECCEB2-8359-11D0-A34E-00AA00BDCDFD Mdt2gddo.dll

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.

How does this vulnerability relate to one of the vulnerabilities that are
corrected by MS05-054?
Both security bulletins address COM object Instantiation Memory Corruption
vulnerabilities. However, this update also addresses new CLSIDs that were
not addressed as part of MS05-054. MS05-054 helps protect against
exploitation of the CLSIDs that are discussed in that bulletin.

Note Customers who have installed the security update included with
Microsoft Security Bulletin
<http://go.microsoft.com/fwlink/?LinkId=50690> MS05-052 or a later
security bulletin for Internet Explorer are not at risk from attacks
originating from the Internet zone.

HTML Tag Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1188>
CVE-2006-1188:
A remote code execution vulnerability exists in the way Internet Explorer
handles HTML elements that contain a specially crafted tag. An attacker
could exploit the vulnerability by constructing a malicious Web page that
could potentially allow remote code execution if a user visited the
malicious Web site. An attacker who successfully exploited this
vulnerability could take complete control of an affected system.

Mitigating Factors for HTML Tag Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1188>
CVE-2006-1188:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability in the e-mail vector because reading e-mail messages in plain text is the default configuration for Outlook Express. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

* This vulnerability does not affect Internet Explorer 5.01 Service Pack
4 on Windows 2000 Service Pack 4.

Workarounds for HTML Tag Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1188>
CVE-2006-1188:
No workarounds have been identified for this vulnerability.

FAQ for HTML Tag Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1188>
CVE-2006-1188:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
When Internet Explorer handles HTML elements containing a specially
crafted tag, it may corrupt system memory in such a way that an attacker
could execute arbitrary code.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user is logged on and reading HTML
e-mail messages or that a user is logged on and visits a Web site for any
malicious action to occur. Therefore, any systems where HTML e-mail
messages are read or where Internet Explorer is used frequently, such as
workstations or terminal servers, are at the most risk from this
vulnerability.

What does the update do?
The update removes the vulnerability by modifying the way that Internet
Explorer handles HTML elements containing the specially crafted tag so
that Internet Explorer does not exit in an exploitable way.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
Yes. This vulnerability has been publicly disclosed. It has been assigned
Common Vulnerability and Exposure number CVE-2006-1188.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had seen examples of proof of concept code published
publicly but had not received any information to indicate that this
vulnerability had been publicly used to attack customers when this
security bulletin was originally issued.

Does applying this security update help protect customers from the code
that has been published publicly that attempts to exploit this
vulnerability?
Yes. This security update addresses the vulnerability that potentially
could be exploited by using the published proof of concept code. The
vulnerability that has been addressed has been assigned the Common
Vulnerability and Exposure number CVE-2006-1188.

Double-Byte Character Parsing Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1189>
CVE-2006-1189:

A remote code execution vulnerability exists in the way Internet Explorer
handles double-byte characters in specially crafted URLs. An attacker
could exploit the vulnerability by constructing a malicious Web page that
could potentially allow remote code execution if a user visited the
malicious Web site. An attacker who successfully exploited this
vulnerability could take complete control of an affected system.

Mitigating Factors for Double-Byte Character Parsing Memory Corruption
Vulnerability - CVE-2006-1189:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability in the e-mail vector because reading e-mail messages in plain text is the default configuration for Outlook Express. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

* This vulnerability does not affect Internet Explorer 5.01 Service Pack
4 on Windows 2000 Service Pack 4 or Internet Explorer 6 for Windows Server
2003 Service Pack 1.

* This vulnerability only affects systems that use Double-Byte Character
Sets. Systems that are affected are Windows language versions that use a
Double Byte Character Sets language. Examples of languages that use DBCS
are Chinese languages, Japanese, and Korean languages. Customers using
other language versions of Windows might also be affected if
<http://www.microsoft.com/globaldev/handson/user/xpintlsupp.mspx> Language
for non-Unicode programs has been set to a Double Byte Character Sets
language.

Workarounds for Double-Byte Character Parsing Memory Corruption
Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1189>
CVE-2006-1189:
No workarounds have been identified for this vulnerability.

FAQ for Double-Byte Character Parsing Memory Corruption Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1189>
CVE-2006-1189:
What is the scope of the vulnerability?
This is a remote code execution vulnerability. An attacker who
successfully exploited this vulnerability could remotely take complete
control of an affected system. An attacker could then install programs;
view, change, or delete data; or create new accounts with full user
rights.

What causes the vulnerability?
When Internet Explorer handles double-byte characters in specially crafted
URLs it may corrupt system memory in such a way that an attacker could
execute arbitrary code.

What are Double-Byte Character Sets?
Double-Byte Character Sets (DBCS) are an expanded 8-bit character set
where the smallest unit is a byte. Some characters in a DBCS have a single
byte code value and some have a double byte code value. A DBCS can be
thought of as the ANSI character set for some Asian versions of Microsoft
Windows. For more information, see the
<http://msdn.microsoft.com/library/en-us/intl/unicode_90c3.asp> product
documentation.

How do I know if I am running a DBCS locale?
DBCS can be thought of as the ANSI character set for some Asian versions
of Microsoft Windows. Examples of languages that use DBCS are Chinese,
Japanese, and Korean languages. For more information about system locales
and how to determine the system locale please visit this Microsoft
<http://www.microsoft.com/globaldev/DrIntl/faqs/Locales.mspx> Web site.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could take
complete control of the affected system. In a Web-based attack scenario,
an attacker would host a Web site that exploits this vulnerability. An
attacker would have no way to force users to visit a malicious Web site.
Instead, an attacker would have to persuade them to visit the Web site,
typically by getting them to click a link that takes them to the
attacker's site. It could also be possible to display malicious Web
content by using banner advertisements or by using other methods to
deliver Web content to affected systems.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site.

What systems are primarily at risk from the vulnerability?
This vulnerability requires that a user is logged on and reading HTML
e-mail messages or that a user is logged on and visits a Web site for any
malicious action to occur. Therefore, any systems where HTML e-mail
messages are read or where Internet Explorer is used frequently, such as
workstations or terminal servers, are at the most risk from this
vulnerability.

Are Windows 98, Windows 98 Second Edition or Windows Millennium Edition
critically affected by this vulnerability?
Yes. Windows 98, Windows 98 Second Edition, and Windows Millennium Edition
are critically affected by this vulnerability. The security updates are
available from the <http://go.microsoft.com/fwlink/?LinkId=21130> Windows
Update Web site. For more information about severity ratings, visit the
following <http://go.microsoft.com/fwlink/?LinkId=21140> Web site.

What does the update do?
The update removes the vulnerability by modifying the way that Internet
Explorer handles double-byte characters in specially crafted URLs.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.

Script Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1190>
CVE-2006-1190:
A vulnerability exists in Internet Explorer in the way it returns
IOleClientSite information when an embedded object is dynamically created.
An attacker could exploit the vulnerability by constructing a malicious
Web page with a dynamically created object. This object would need to make
use of the IOleClientSite information returned to make a security related
decision. This could potentially allow remote code execution or
information disclosure if a user visited the malicious Web site. An
attacker who successfully exploited this vulnerability could take complete
control of an affected system.

Mitigating Factors for Script Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1190>
CVE-2006-1190:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

* This vulnerability does not affect Internet Explorer 5.01 Service Pack
4 on Windows 2000 Service Pack 4

Workarounds for Script Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1190>
CVE-2006-1190:
Microsoft has tested the following workarounds. While these workarounds
will not correct the underlying vulnerability, they help block known
attack vectors. When a workaround reduces functionality, it is identified
in the following section.

* Configure Internet Explorer to prompt before running ActiveX Controls
or disable ActiveX Controls in the Internet and Local intranet security
zone

You can help protect against this vulnerability by changing your settings
to prompt before running ActiveX Controls or to disable ActiveX Controls
in the Internet and Local intranet security zone. To do this, follow these
steps:

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the ActiveX controls and plug-ins section, under
Run ActiveX controls and plug-ins, click Prompt or Disable, and then click
OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the ActiveX controls and plug-ins section, under
Run ActiveX controls and plug-ins, click Prompt or Disable, and then click
OK.
7. Click OK two times to return to Internet Explorer.

Note Disabling ActiveX Controls in the Internet and Local intranet
security zones may cause some Web sites to work incorrectly. If you have
difficulty using a Web site after you change this setting, and you are
sure the site is safe to use, you can add that site to your list of
trusted sites. This will allow the site to work correctly.

Impact of Workaround: There are side effects to prompting before running
ActiveX Controls. Many Web sites that are on the Internet or on an
intranet use ActiveX to provide additional functionality. For example, an
online e-commerce site or banking site may use ActiveX Controls to provide
menus, ordering forms, or even account statements. Prompting before
running ActiveX Controls is a global setting that affects all Internet and
intranet sites. You will be prompted frequently when you enable this
workaround. For each prompt, if you feel you trust the site that you are
visiting, click Yes to run ActiveX Controls. If you do not want to be
prompted for all these sites, use the steps outlined in "Add sites that
you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Configure Internet Explorer to prompt before running Active Scripting or
disable Active Scripting in the Internet and Local intranet security zone

You can help protect against this vulnerability by changing your settings
to prompt before running Active Scripting or to disable Active Scripting
in the Internet and Local intranet security zone. To do this, follow these
steps:

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
7. Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet
security zones may cause some Web sites to work incorrectly. If you have
difficulty using a Web site after you change this setting, and you are
sure the site is safe to use, you can add that site to your list of
trusted sites. This will allow the site to work correctly.

Impact of Workaround: There are side effects to prompting before running
Active Scripting. Many Web sites that are on the Internet or on an
intranet use Active Scripting to provide additional functionality. For
example, an online e-commerce site or banking site may use Active
Scripting to provide menus, ordering forms, or even account statements.
Prompting before running Active Scripting is a global setting that affects
all Internet and intranet sites. You will be prompted frequently when you
enable this workaround. For each prompt, if you feel you trust the site
that you are visiting, click Yes to run Active Scripting. If you do not
want to be prompted for all these sites, use the steps outlined in "Add
sites that you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Set Internet and Local intranet security zone settings to High to prompt
before running ActiveX Controls and Active Scripting in these zones

You can help protect against this vulnerability by changing your settings
for the Internet security zone to prompt before running ActiveX controls.
You can do this by setting your browser security to High.

To raise the browsing security level in Microsoft Internet Explorer,
follow these steps:

1. On the Internet Explorer Tools menu, click Internet Options.
2. In the Internet Options dialog box, click the Security tab, and then
click the Internet icon.
3. Under Security level for this zone, move the slider to High. This sets
the security level for all Web sites you visit to High.

Note If no slider is visible, click Default Level, and then move the
slider to High.

Note Setting the level to High may cause some Web sites to work
incorrectly. If you have difficulty using a Web site after you change this
setting, and you are sure the site is safe to use, you can add that site
to your list of trusted sites. This will allow the site to work correctly
even with the security setting set to High.

Impact of Workaround: There are side effects to prompting before running
ActiveX Controls and Active Scripting. Many Web sites that are on the
Internet or on an intranet use ActiveX or Active Scripting to provide
additional functionality. For example, an online e-commerce site or
banking site may use ActiveX Controls to provide menus, ordering forms, or
even account statements. Prompting before running ActiveX Controls or
Active Scripting is a global setting that affects all Internet and
intranet sites. You will be prompted frequently when you enable this
workaround. For each prompt, if you feel you trust the site that you are
visiting, click Yes to run ActiveX Controls or Active Scripting. If you do
not want to be prompted for all these sites, use the steps outlined in
"Add sites that you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

FAQ for Script Execution Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1190>
CVE-2006-1190:

What is the scope of the vulnerability?
A vulnerability exists in Internet Explorer that could potentially allow
remote code execution or information disclosure. An attacker who
successfully exploited this could at worst remotely take complete control
of an affected system. An attacker could then install programs; view,
change, or delete data; or create new accounts with full user rights.

What causes the vulnerability?
Internet Explorer may return erroneous IOleClientSite information when an
embedded object is dynamically created. This could allow this object to
use the IOleClientSite information returned to make an incorrect security
related decision and run in the context of the wrong site or the wrong
Internet Explorer security zone.

What is IOleClientSite?
The IOleClientSite interface is the primary means by which an embedded
object obtains information about the location and extent of its display
site, its moniker, its user interface, and other resources provided by its
container. For more information, see the
<http://msdn.microsoft.com/library/en-us/com/htm/oin_oc_5l2d.asp> product
documentation.

What are Internet Explorer security zones?
Internet Explorer
<http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q174360> security
zones are part of a system that divides online content into categories or
zones, based on the trustworthiness of the content. Specific Web domains
can be assigned to a zone, depending on how much trust is put in the
content of each domain. The zone then restricts the capabilities of the
Web content, based on the zone's policy. By default, most Internet domains
are treated as part of the Internet zone. By default, the policy of the
Internet zone prevents scripts and other active code from accessing
resources on the local system.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could gain the
same user rights as the local user. Users whose accounts are configured to
have fewer user rights on the system could be less impacted than users who
operate with administrative user rights.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires a user to be logged on and visiting a Web site
for any malicious action to occur. Therefore, any systems where Internet
Explorer is used frequently, such as workstations or terminal servers, are
at the most risk from this vulnerability.

What does the update do?
The update removes the vulnerability by modifying Internet Explorer so
that it returns the correct IOleClientSite information.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.

Cross-Domain Information Disclosure Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1191>
CVE-2006-1191:
An information disclosure vulnerability exists in Internet Explorer
because of the way that it handles navigation methods. An attacker could
exploit the vulnerability by constructing a malicious Web page that could
potentially lead to information disclosure if a user visited a malicious
Web site or viewed a specially crafted e-mail message. An attacker who
successfully exploited this vulnerability could read cookies or other data
from another Internet Explorer domain. However, user interaction is
required to exploit this vulnerability.

Mitigating Factors for Cross-Domain Information Disclosure Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1191>
CVE-2006-1191:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* An attacker who successfully exploited this vulnerability could gain
access to read cookies or other data from a system other than that of the
attacker s Web site.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability in the e-mail vector because reading e-mail messages in plain text is the default configuration for Outlook Express. See the FAQ section of this security update for more information about Internet Explorer Enhanced Security Configuration.

* This vulnerability does not affect the following versions of Windows:
* Windows 2000 Service Pack 4
* Windows XP Service Pack 1
* Windows XP Professional x64 Edition
* Windows Server 2003
* Windows Server 2003 for Itanium-based Systems and Windows Server 2003
with Service Pack 1 for Itanium-based Systems
* Windows Server 2003 x64 Edition
* Windows 98, Windows 98 Second Edition (SE), and Windows Millennium
Edition (ME)

Workarounds for Cross-Domain Information Disclosure Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1191>
CVE-2006-1191:
Microsoft has tested the following workarounds. While these workarounds
will not correct the underlying vulnerability, they help block known
attack vectors. When a workaround reduces functionality, it is identified
in the following section.

* Configure Internet Explorer to prompt before running Active Scripting
or disable Active Scripting in the Internet and Local intranet security
zone

You can help protect against this vulnerability by changing your settings
to prompt before running Active Scripting or to disable Active Scripting
in the Internet and Local intranet security zone. To do this, follow these
steps:

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the Scripting section, under Active Scripting,
click Prompt or Disable, and then click OK.
7. Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet
security zones may cause some Web sites to work incorrectly. If you have
difficulty using a Web site after you change this setting, and you are
sure the site is safe to use, you can add that site to your list of
trusted sites. This will allow the site to work correctly.

Impact of Workaround: There are side effects to prompting before running
Active Scripting. Many Web sites that are on the Internet or on an
intranet use Active Scripting to provide additional functionality. For
example, an online e-commerce site or banking site may use Active
Scripting to provide menus, ordering forms, or even account statements.
Prompting before running Active Scripting is a global setting that affects
all Internet and intranet sites. You will be prompted frequently when you
enable this workaround. For each prompt, if you feel you trust the site
that you are visiting, click Yes to run Active Scripting. If you do not
want to be prompted for all these sites, use the steps outlined in "Add
sites that you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

Set Internet and Local intranet security zone settings to High to prompt
before running ActiveX Controls and Active Scripting in these zones

You can help protect against this vulnerability by changing your settings
for the Internet security zone to prompt before running ActiveX controls.
You can do this by setting your browser security to High.

To raise the browsing security level in Microsoft Internet Explorer,
follow these steps:

1. On the Internet Explorer Tools menu, click Internet Options.
2. In the Internet Options dialog box, click the Security tab, and then
click the Internet icon.
3. Under Security level for this zone, move the slider to High. This sets
the security level for all Web sites you visit to High.

Note If no slider is visible, click Default Level, and then move the
slider to High.

Note Setting the level to High may cause some Web sites to work
incorrectly. If you have difficulty using a Web site after you change this
setting, and you are sure the site is safe to use, you can add that site
to your list of trusted sites. This will allow the site to work correctly
even with the security setting set to High.

Impact of Workaround: There are side effects to prompting before running
ActiveX Controls and Active Scripting. Many Web sites that are on the
Internet or on an intranet use ActiveX or Active Scripting to provide
additional functionality. For example, an online e-commerce site or
banking site may use ActiveX Controls to provide menus, ordering forms, or
even account statements. Prompting before running ActiveX Controls or
Active Scripting is a global setting that affects all Internet and
intranet sites. You will be prompted frequently when you enable this
workaround. For each prompt, if you feel you trust the site that you are
visiting, click Yes to run ActiveX Controls or Active Scripting. If you do
not want to be prompted for all these sites, use the steps outlined in
"Add sites that you trust to Internet Explorer's Trusted sites zone .

Add sites that you trust to Internet Explorer's Trusted sites zone.

After you set Internet Explorer to require a prompt before it runs ActiveX
controls and Active Scripting in the Internet zone and in the Local
intranet zone, you can add sites that you trust to Internet Explorer's
Trusted sites zone. This will allow you to continue to use trusted Web
sites exactly as you do today, while helping to protect you from this
attack on untrusted sites. We recommend that you add only sites that you
trust to the Trusted sites zone.

To do this, follow these steps:

1. In Internet Explorer, click Tools, click Internet Options, and then
click the Security tab.
2. In the Select a Web content zone to specify its current security
settings box, click Trusted Sites, and then click Sites.
3. If you want to add sites that do not require an encrypted channel,
click to clear the Require server verification (https:) for all sites in
this zone check box.
4. In the Add this Web site to the zone box, type the URL of a site that
you trust, and then click Add.
5. Repeat these steps for each site that you want to add to the zone.
6. Click OK two times to accept the changes and return to Internet
Explorer.

Note Add any sites that you trust not to take malicious action on your
computer. Two in particular that you may want to add are
"*.windowsupdate.microsoft.com" and *.update.microsoft.com (without the
quotation marks). These are the sites that will host the update, and it
requires an ActiveX Control to install the update.

FAQ for Cross-Domain Information Disclosure Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1191>
CVE-2006-1191:
What is the scope of the vulnerability?
This is an information disclosure vulnerability. An attacker could exploit
the vulnerability by constructing a malicious Web page that could
potentially lead to information disclosure or spoofing if a user visited a
malicious Web site. An attacker who successfully exploited this
vulnerability could read cookies or other data from another Internet
Explorer domain. However, user interaction is required to exploit this
vulnerability.

What causes the vulnerability?
Internet Explorer allows script to run in a browser window after a
navigation to another site has been performed.

What are Internet Explorer security zones?
Internet Explorer
<http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q174360> security
zones are part of a system that divides online content into categories or
zones, based on the trustworthiness of the content. Specific Web domains
can be assigned to a zone, depending on how much trust is put in the
content of each domain. The zone then restricts the capabilities of the
Web content, based on the zone's policy. By default, most Internet domains
are treated as part of the Internet zone. By default, the policy of the
Internet zone prevents scripts and other active code from accessing
resources on the local system.

What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could read
cookies or other data from another security zone or domain in Internet
Explorer.

How could an attacker exploit the vulnerability?
An attacker could host a malicious Web site that is designed to exploit
this vulnerability through Internet Explorer and then persuade a user to
view the Web site. This can also include Web sites that accept
user-provided content or advertisements, Web sites that host user-provided
content or advertisements, and compromised Web sites. These Web sites
could contain malicious content that could exploit this vulnerability. In
all cases, however, an attacker would have no way to force users to visit
these Web sites. Instead, an attacker would have to persuade users to
visit the Web site, typically by getting them to click a link in an e-mail
message or in an Instant Messenger request that takes users to the
attacker's Web site. It could also be possible to display specially
crafted Web content by using banner advertisements or by using other
methods to deliver Web content to affected systems.

What systems are primarily at risk from the vulnerability?
This vulnerability requires a user to be logged on and visiting a Web site
for any malicious action to occur. Therefore, any systems where Internet
Explorer is used frequently, such as workstations or terminal servers, are
at the most risk from this vulnerability.

What does the update do?
The update removes the vulnerability by changing Internet Explorer so that
it correctly identifies the domain from which the browser window
originated.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.

Address Bar Spoofing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1192>
CVE-2006-1192:
A spoofing vulnerability exists in Internet Explorer that could allow an
attacker to display spoofed content in a browser window. The address bar
and other parts of the trust UI has been navigated away from the attacker
s Web site but the content of the window still contains the attacker s Web
page.

Mitigating Factors for Address Bar Spoofing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1192>
CVE-2006-1192:
* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Web page that is used to exploit this vulnerability.
An attacker would have no way to force users to visit a malicious Web
site. Instead, an attacker would have to persuade them to visit the Web
site, typically by getting them to click a link that takes them to the
attacker's Web site.

* Interacting with the Web page, for instance, by clicking on it, will
cause the content to refresh and display the Web site identified by the
address bar.

* The Restricted sites zone helps reduce attacks that could try to
exploit this vulnerability by preventing Active Scripting from being used
when reading HTML e-mail messages. However, if a user clicks a link in an
e-mail message, they could still be vulnerable to this issue through the
Web-based attack scenario.

By default, Outlook Express 6, Outlook 2002, and Outlook 2003 open HTML
e-mail messages in the Restricted sites zone. Additionally Outlook 2000
opens HTML e-mail messages in the Restricted sites zone if the
<http://go.microsoft.com/fwlink/?LinkId=33334> Outlook E-mail Security
Update has been installed. Outlook Express 5.5 Service Pack 2 opens HTML
e-mail messages in the Restricted sites zone if Microsoft Security
Bulletin <http://go.microsoft.com/fwlink/?LinkId=19527> MS04-018 has been
installed.

* By default, Internet Explorer on Windows Server 2003 runs in a
restricted mode that is known as
<http://msdn.microsoft.com/library/default.asp?url=/workshop/security/szone/overview/esc_changes.asp> Enhanced Security Configuration. This mode mitigates this vulnerability. See the FAQ section or this security update for more information about Internet Explorer Enhanced Security Configuration.

Workarounds for Address Bar Spoofing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1192>
CVE-2006-1192:
No workarounds have been identified for this vulnerability.

FAQ for Address Bar Spoofing Vulnerability -
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1192>
CVE-2006-1192:
What is the scope of the vulnerability?
This is a spoofing vulnerability in Internet Explorer. The vulnerability
could allow an attacker to display spoofed content in a browser window.
Interacting with the Web page, for instance, by clicking on it, will cause
the content to refresh and display the Web site pointed out by the address
bar.

What causes the vulnerability?
It is possible to navigate the Internet Explorer address bar and other
parts of the trust UI away from the attacker s Web site but persist the
content of the window.

How could an attacker exploit the vulnerability?
An attacker could use this vulnerability to create a Web page that would
display a URL of the attacker's choosing in the Address bar, while
displaying a different Web site in the browser window. An attacker could
use this vulnerability to create a malicious page that spoofs a legitimate
site. However, it would not be possible to interact with this same Web
site.

What systems are primarily at risk from the vulnerability?
This vulnerability requires a user to be logged on and visiting a Web site
for any malicious action to occur. Therefore, any systems where Internet
Explorer is used frequently, such as workstations or terminal servers, are
at the most risk from this vulnerability.

What does the update do?
The update removes the vulnerability by not allowing the window content to
persist after navigation has occurred.

When this security bulletin was issued, had this vulnerability been
publicly disclosed?
No. Microsoft received information about this vulnerability through
responsible disclosure.

When this security bulletin was issued, had Microsoft received any reports
that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this
vulnerability had been publicly used to attack customers and had not seen
any examples of proof of concept code published when this security
bulletin was originally issued.


ADDITIONAL INFORMATION

The information has been provided by Microsoft Security.
The original article can be found at:
<http://www.microsoft.com/technet/security/Bulletin/MS06-013.mspx>
http://www.microsoft.com/technet/security/Bulletin/MS06-013.mspx



========================================


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