[NT] Microsoft Excel Code Execution (MS07-002)



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Microsoft Excel Code Execution (MS07-002)
------------------------------------------------------------------------


SUMMARY

This update resolves several newly discovered, privately reported
vulnerabilities. An attacker who successfully exploited the most severe of
these vulnerabilities could 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.

DETAILS

Affected Software:
* Microsoft Office 2000 Service Pack 3
* Microsoft Excel 2000 Download the update (
<http://www.microsoft.com/downloads/details.aspx?familyid=5CCF4455-6B22-4249-93D7-661D12839292> KB925524)
* Microsoft Office XP Service Pack 3
* Microsoft Excel 2002 Download the update (
<http://www.microsoft.com/downloads/details.aspx?FamilyId=EE7278EA-3AEE-4994-9657-66019961D63C> KB925523)
* Microsoft Office 2003 Service Pack 2
* Microsoft Excel 2003 Download the update (
<http://www.microsoft.com/downloads/details.aspx?FamilyId=79B88CE8-5C56-462F-AC1A-4BCE04C8F543> KB925257)
* Microsoft Office Excel Viewer 2003 Download the update (
<http://www.microsoft.com/downloads/details.aspx?FamilyId=99AE7653-F0FD-4DBA-A151-098FD03E6EA4> KB925525)
* Microsoft Works Suites
* Microsoft Works Suite 2004 - Download the update (
<http://www.microsoft.com/downloads/details.aspx?FamilyId=EE7278EA-3AEE-4994-9657-66019961D63C> KB925523) (same as the Microsoft Excel 2002 update)
* Microsoft Works Suite 2005 - Download the update (
<http://www.microsoft.com/downloads/details.aspx?FamilyId=EE7278EA-3AEE-4994-9657-66019961D63C> KB925523) (same as the Microsoft Excel 2002 update)
* Microsoft Office 2004 for Mac - Download the update (
<http://www.microsoft.com/mac/> KB930402)
* Microsoft Office v. X for Mac - Download the update (
<http://www.microsoft.com/mac/> KB930403)

Non-Affected Software:
* 2007 Microsoft Office system
* Microsoft Office Excel 2007
* Microsoft Works Suites:
* Microsoft Works Suite 2006

Excel Malformed IMDATA Record Vulnerability - CVE-2007-0027:
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed IMDATA record.

If a user is logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

Mitigating Factors for Excel Malformed IMDATA Record Vulnerability -
CVE-2007-0027:
* 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.

* In a Web-based attack scenario, an attacker would have to host a Web
site that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

* The vulnerability cannot be exploited automatically through e-mail. For
an attack to be successful a user must open an attachment that is sent in
an e-mail message.

* Users who have installed and are using the
<http://www.microsoft.com/downloads/details.aspx?familyid=8B5762D2-077F-4031-9EE6-C9538E9F2A2F> Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancel before opening a document. The features of the Office Document Open Confirmation Tool are incorporated in Office XP and Office 2003.

Workarounds for Excel Malformed IMDATA Record Vulnerability -
CVE-2007-0027:
Do not open or save Microsoft Excel files that you receive from untrusted
sources or that you receive unexpectedly from trusted sources. This
vulnerability could be exploited when a user opens a specially crafted
file.

FAQ for Excel Malformed IMDATA Record Vulnerability - CVE-2007-0027:
What is the scope of the vulnerability?
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed IMDATA record.

If a user is logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. 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.

What causes the vulnerability?
Excel does not perform sufficient data validation when processing the
contents of a file. When Excel opens a specially crafted Excel file and
parses a malformed IMDATA record, 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 take
complete control of the affected system.

How could an attacker exploit the vulnerability?
In an e-mail attack scenario, an attacker could exploit the vulnerability
by sending a specially crafted file to the user and by persuading the user
to open the file.

In a Web-based attack scenario, an attacker would have to host a Web site
that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be
at more risk if administrators allow users to log on to servers and to run
programs. However, best practices strongly discourage allowing this.

What does the update do?
The update removes the vulnerability by modifying the way that Excel
parses the file and validates a record before passing it to the allocated
buffer.

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.

Excel Malformed Record Vulnerability - CVE-2007-0028:
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed record.

If a user is logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

Mitigating Factors for Excel Malformed Record Vulnerability -
CVE-2007-0028:
* 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.

* In a Web-based attack scenario, an attacker would have to host a Web
site that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

* The vulnerability cannot be exploited automatically through e-mail. For
an attack to be successful a user must open an attachment that is sent in
an e-mail message.

* Users who have installed and are using the
<http://www.microsoft.com/downloads/details.aspx?familyid=8B5762D2-077F-4031-9EE6-C9538E9F2A2F> Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancel before opening a document. The features of the Office Document Open Confirmation Tool are incorporated in Office XP and Office 2003.

Workarounds for Excel Malformed Record Vulnerability - CVE-2007-0028:
Do not open or save Microsoft Excel files that you receive from untrusted
sources or that you receive unexpectedly from trusted sources. This
vulnerability could be exploited when a user opens a specially crafted
file.

FAQ for Excel Malformed Record Vulnerability - CVE-2007-0028:
What is the scope of the vulnerability?
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed record.

If a user is logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

What causes the vulnerability?
Excel does not perform sufficient data validation when processing the
contents of a file. When Excel opens a specially crafted Excel file and
parses a malformed record, 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 take
complete control of the affected system.

How could an attacker exploit the vulnerability?
In an e-mail attack scenario, an attacker could exploit the vulnerability
by sending a specially crafted file to the user and by persuading the user
to open the file.

In a Web-based attack scenario, an attacker would have to host a Web site
that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be
at more risk if administrators allow users to log on to servers and to run
programs. However, best practices strongly discourage allowing this.

What does the update do?
The update removes the vulnerability by modifying the way that Excel
parses the file and validates a record before passing it to the allocated
buffer.

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.

Excel Malformed String Vulnerability - CVE-2007-0029:
A remote code execution vulnerability exists in Microsoft Excel that could
allow an attacker who successfully exploited this vulnerability to take
complete control of the affected system.

If a user were logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

Mitigating Factors for Excel Malformed String Vulnerability -
CVE-2007-0029:
* 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.

* In a Web-based attack scenario, an attacker would have to host a Web
site that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

* The vulnerability cannot be exploited automatically through e-mail. For
an attack to be successful a user must open an attachment that is sent in
an e-mail message.

* Users who have installed and are using the
<http://www.microsoft.com/downloads/details.aspx?familyid=8B5762D2-077F-4031-9EE6-C9538E9F2A2F> Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancel before opening a document. The features of the Office Document Open Confirmation Tool are incorporated in Office XP and Office 2003.

Workarounds for Excel Malformed String Vulnerability - CVE-2007-0029:
Do not open or save Microsoft Excel files that you receive from untrusted
sources or that you receive unexpectedly from trusted sources. This
vulnerability could be exploited when a user opens a specially crafted
file.

FAQ for Excel Malformed String Vulnerability - CVE-2007-0029:
What is the scope of the vulnerability?
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed string.

If a user were logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

What causes the vulnerability?
Excel does not perform sufficient data validation when processing the
contents of a file. When Excel opens a specially crafted Excel file and
parses a malformed string 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 take
complete control of the affected system.

How could an attacker exploit the vulnerability?
In an e-mail attack scenario, an attacker could exploit the vulnerability
by sending a specially crafted file to the user and by persuading the user
to open the file.

In a Web-based attack scenario, an attacker would have to host a Web site
that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be
at more risk if administrators allow users to log on to servers and to run
programs. However, best practices strongly discourage allowing this.

What does the update do?
The update removes the vulnerability by modifying the way that Excel
parses the file and validates a string before passing it to the allocated
buffer.

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.

Excel Malformed Column Record Vulnerability - CVE-2007-0030:
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed Column record.

If a user were logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

Mitigating Factors for Excel Malformed Column Record Vulnerability -
CVE-2007-0030:
* 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.

* In a Web-based attack scenario, an attacker would have to host a Web
site that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

* The vulnerability cannot be exploited automatically through e-mail. For
an attack to be successful a user must open an attachment that is sent in
an e-mail message.

* Users who have installed and are using the
<http://www.microsoft.com/downloads/details.aspx?familyid=8B5762D2-077F-4031-9EE6-C9538E9F2A2F> Office Document Open Confirmation Tool for Office 2000 will be prompted with Open, Save, or Cancel before opening a document. The features of the Office Document Open Confirmation Tool are incorporated in Office XP and Office 2003.

Workarounds for Excel Malformed Column Record Vulnerability -
CVE-2007-0030:
Do not open or save Microsoft Excel files that you receive from untrusted
sources or that you receive unexpectedly from trusted sources. This
vulnerability could be exploited when a user opens a specially crafted
file.

FAQ for Excel Malformed Column Record Vulnerability - CVE-2007-0030:
What is the scope of the vulnerability?
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed Column record.

If a user were logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

What causes the vulnerability?
Excel does not perform sufficient data validation when processing the
contents of a file. When Excel opens a specially crafted Excel file and
parses a malformed Column record, 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 take
complete control of the affected system.

How could an attacker exploit the vulnerability?
In an e-mail attack scenario, an attacker could exploit the vulnerability
by sending a specially crafted file to the user and by persuading the user
to open the file.

In a Web-based attack scenario, an attacker would have to host a Web site
that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be
at more risk if administrators allow users to log on to servers and to run
programs. However, best practices strongly discourage allowing this.

What does the update do?
The update removes the vulnerability by modifying the way that Excel
parses the file and validates a Column record before passing it to the
allocated buffer.

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.

Excel Malformed Palette Record Vulnerability - CVE-2007-0031:
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed Palette record.

If a user were logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

Mitigating Factors for Excel Malformed Palette Record Vulnerability -
CVE-2007-0031:
* 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.

* In a Web-based attack scenario, an attacker would have to host a Web
site that contains a Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

* The vulnerability cannot be exploited automatically through e-mail. For
an attack to be successful a user must open an attachment that is sent in
an e-mail message.

* Users who have installed and are using the Office Document Open
Confirmation Tool for Office 2000 will be prompted with Open, Save, or
Cancel before opening a document. The features of the Office Document Open
Confirmation Tool are incorporated in Office XP and Office 2003.

Workarounds for Excel Malformed Palette Record Vulnerability -
CVE-2007-0031:
* Do not open or save Microsoft Excel files that you receive from
untrusted sources or that you receive unexpectedly from trusted sources.
This vulnerability could be exploited when a user opens a specially
crafted file.

FAQ for Excel Malformed Palette Record Vulnerability - CVE-2007-0031:
What is the scope of the vulnerability?
A remote code execution vulnerability exists in Microsoft Excel. An
attacker could exploit this vulnerability when Excel parses a file and
processes a malformed Palette record.

If a user were logged on with administrative user rights, an attacker who
successfully exploited this vulnerability could 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. Users whose
accounts are configured to have fewer user rights on the system could be
less affected than users who operate with administrative user rights.

What causes the vulnerability?
Excel does not perform sufficient data validation when processing the
contents of a file. When Excel opens a specially crafted Excel file and
parses a malformed Palette record, 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 take
complete control of the affected system.

How could an attacker exploit the vulnerability?
In an e-mail attack scenario, an attacker could exploit the vulnerability
by sending a specially crafted file to the user and by persuading the user
to open the file.

In a Web-based attack scenario, an attacker would have to host a Web site
that contains an Excel file that is used to attempt to exploit this
vulnerability. In addition, compromised Web sites and Web sites that
accept or host user-provided content could contain specially crafted
content that could 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 site.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be
at more risk if administrators allow users to log on to servers and to run
programs. However, best practices strongly discourage allowing this.

What does the update do?
The update removes the vulnerability by modifying the way that Excel
parses the file and validates a Palette record before passing it to the
allocated buffer.

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 Bulletin MS07-002.
The original article can be found at:
<http://www.microsoft.com/technet/security/bulletin/ms07-002.mspx>
http://www.microsoft.com/technet/security/bulletin/ms07-002.mspx



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