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HistoryJul 11, 2006 - 12:00 a.m.

Microsoft Security Bulletin MS06-037 Vulnerabilities in Microsoft Excel Could Allow Remote Code Execution (917285)

2006-07-1100:00:00
vulners.com
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Microsoft Security Bulletin MS06-037
Vulnerabilities in Microsoft Excel Could Allow Remote Code Execution (917285)
Published: July 11, 2006

Version: 1.0
Summary

Who Should Read this Document: Customers who use Microsoft Excel

Impact of Vulnerability: Remote Code Execution

Maximum Severity Rating: Critical

Recommendation: Customers should apply the update immediately

Security Update Replacement: This bulletin replaces a prior security update. See the frequently asked questions (FAQ) section of this bulletin for the complete list.

Caveats: None

Tested Software and Security Update Download Locations:

Affected Software:

Microsoft Office 2003 Service Pack 1 or Service Pack 2

Microsoft Excel 2003 — Download the update (KB918419)

Microsoft Excel Viewer 2003 - Download the update (KB918425)

Microsoft Office XP Service Pack 3

Microsoft Excel 2002 — Download the update (KB918420)

Microsoft Office 2000 Service Pack 3

Microsoft Excel 2000 — Download the update (KB918424)

Microsoft Office 2004 for Mac

Microsoft Excel 2004 for Mac - Download the update (KB921213)

Microsoft Office v. X for Mac

Microsoft Excel v. X for Mac - Download the update (KB921214)

The software in this list has been tested to determine whether the versions are affected. Other versions either no longer include security update support or may not be affected. To determine the support life cycle for your product and version, visit the Microsoft Support Lifecycle Web site.
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General Information

Executive Summary

This update resolves several newly discovered, privately reported and public vulnerabilities. Each vulnerability is documented in this bulletin in its own "Vulnerability Details" section.

When using vulnerable versions of Office, if a user were logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of the client workstation. 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.

We recommend that customers apply the update immediately

Severity Ratings and Vulnerability Identifiers:
Vulnerability Identifiers Impact of Vulnerability Microsoft Excel 2003 and Excel Viewer 2003 Microsoft Excel 2002 Microsoft Excel 2000 Microsoft Excel 2004 for Mac and Microsoft Excel v. X for Mac

Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1301

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1302

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed COLINFO record Vulnerability - CVE-2006-1304

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed OBJECT record Vulnerability - CVE-2006-1306

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed FNGROUPCOUNT value Vulnerability - CVE-2006-1308

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed LABEL record Vulnerability - CVE-2006-1309

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed File Vulnerability –

CVE-2006-2388

Remote Code Execution

Important

Important

Critical

Important

Microsoft Excel Malformed File Vulnerability –

CVE-2006-3059

Remote Code Execution

Important

Important

Critical

Important

Aggregate Severity of All Vulnerabilities

Important

Important

Critical

Important

This assessment is based on the types of systems that are affected by the vulnerability, their typical deployment patterns, and the effect that exploiting the vulnerability would have on them.
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Frequently Asked Questions (FAQ) Related to This Security Update

Why does this update address several reported security vulnerabilities?
This update addresses for several vulnerabilities because the modifications that are required to address these issues are located in related files. Instead of having to install several updates that are almost the same, customers can install only this update.

What updates does this release replace?
This security update replaces a prior security update. The security bulletin ID and affected applications are listed in the following table.
Bulletin ID Excel 2000 Microsoft Excel 2002, Excel 2003, and Excel Viewer 2003 Microsoft Excel 2004 for Mac and Microsoft Excel v. X for Mac

MS06-012

Replaced

Replaced

Replaced

Can I use the Microsoft Baseline Security Analyzer (MBSA) to determine whether this update is required?

The following table provides the MBSA detection summary for this security update.
Software MBSA 1.2.1 MBSA 2.0

Microsoft Excel 2000

Yes

No

Microsoft Excel 2002

Yes

Yes

Microsoft Excel 2003

Yes

Yes

Microsoft Excel 2004 for Mac

No

No

Microsoft Excel v. X for Mac

No

No

Note MBSA 1.2.1 uses an integrated version of the Office Detection Tool (ODT) which does not support remote scans of this security update. For more information about MBSA, visit the MBSA Web site.

For more information about MBSA, visit the MBSA Web site. For more information about MBSA support, visit the following Microsoft Baseline Security Analyzer 1.2 Q&A Web site.

For more information about the programs that Microsoft Update and MBSA 2.0 currently do not detect, see Microsoft Knowledge Base Article 895660.

Can I use Systems Management Server (SMS) to determine whether this update is required?

The following table provides the SMS summary for this security update.
Software SMS 2.0 SMS 2003

Microsoft Excel 2000

Yes

No

Microsoft Excel 2002

Yes

Yes

Microsoft Excel 2003

Yes

Yes

Microsoft Excel 2004 for Mac

No

No

Microsoft Excel v. X for Mac

No

No

SMS uses MBSA for detection. Therefore, SMS has the same limitation that is listed earlier in this bulletin related to programs that MBSA does not detect.

For SMS 2.0, the SMS SUS Feature Pack, which includes the Security Update Inventory Tool, can be used by SMS to detect security updates. SMS SUIT uses the MBSA 1.2.1 engine for detection. For more information about the Security Update Inventory Tool, visit the following Microsoft Web site. For more information about the limitations of the Security Update Inventory Tool, see Microsoft Knowledge Base Article 306460. The SMS SUS Feature Pack also includes the Microsoft Office Inventory Tool to detect required updates for Microsoft Office applications.

For SMS 2003, the SMS 2003 Inventory Tool for Microsoft Updates can be used by SMS to detect security updates that are offered by Microsoft Update and that are supported by Windows Server Update Services. For more information about the SMS 2003 Inventory Tool for Microsoft Updates, visit the following Microsoft Web site. SMS 2003 can also use the Microsoft Office Inventory Tool to detect required updates for Microsoft Office applications.

For more information about SMS, visit the SMS Web site.
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Vulnerability Details

Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1301

A remote code execution vulnerability exists in Excel that results from the processing of a malformed SELECTION record. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

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 Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1301:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1301:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.

This vulnerability could be exploited when a user opens a file.
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FAQ for Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1301:

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.

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?
When Excel opens a specially crafted Excel file that results from the processing of a malformed SELECTION 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 any action on the system that the user who opened the file could take.

How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message to the allocated buffer.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. While the initial report was provided through responsible disclosure, the vulnerability was later disclosed publicly. This security bulletin addresses the publicly disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
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Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1302

A remote code execution vulnerability exists in Excel that results from processing of a malformed SELECTION record. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

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 Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1302:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
Top of sectionTop of section

Workarounds for Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1302:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.
This vulnerability could be exploited when a user opens a file.
Top of sectionTop of section

FAQ for Microsoft Excel Malformed SELECTION record Vulnerability - CVE-2006-1302:

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.

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?
When Excel opens a specially crafted Excel file that results from the processing of a SELECTION 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 any action on the system that the user who opened the file could take.

How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message 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. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
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Microsoft Excel Malformed COLINFO record Vulnerability - CVE-2006-1304

A remote code execution vulnerability exists in Excel that results from processing of a malformed COLINFO record. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

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 Microsoft Excel Malformed COLINFO record Vulnerability - CVE-2006-1304

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
Top of sectionTop of section

Workarounds for Microsoft Excel Malformed COLINFO record Vulnerability - CVE-2006-1304:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.
This vulnerability could be exploited when a user opens a file.
Top of sectionTop of section

FAQ for Microsoft Excel Malformed COLINFO record Vulnerability - CVE-2006-1304:

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.

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?
When Excel opens a specially crafted Excel file that results from the processing of a malformed COLINFO 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 any action on the system that the user who opened the file could take.

How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a message before it passes the message 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. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
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Microsoft Excel Malformed OBJECT Record Vulnerability - CVE-2006-1306

A remote code execution vulnerability exists in Excel that results from processing of a malformed OBJECT record. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

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 Microsoft Excel Remote Code Execution Using a Malformed OBJECT Record Vulnerability - CVE-2006-1306:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Excel Malformed OBJECT Record Vulnerability - CVE-2006-1306:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.
This vulnerability could be exploited when a user opens a file.
Top of sectionTop of section

FAQ for Microsoft Malformed OBJECT Record Vulnerability - CVE-2006-1306:

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.

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?
When Excel opens a specially crafted Excel that results from the processing of a malformed object 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 any action on the system that the user who opened the file could take

How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message 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. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
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Microsoft Excel Malformed FNGROUPCOUNT Value Vulnerability - CVE-2006-1308

A remote code execution vulnerability exists in Excel that results from the processing of a malformed FNGROUPCOUNT value file. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

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 Microsoft Excel Malformed FNGROUPCOUNT Value Vulnerability - CVE-2006-1308:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
Top of sectionTop of section

Workarounds for Microsoft Excel Malformed FNGROUPCOUNT Value Vulnerability - CVE-2006-1308:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.
This vulnerability could be exploited when a user opens a file.
Top of sectionTop of section

FAQ for Microsoft Excel Malformed FNGROUPCOUNT Value Vulnerability - CVE-2006-1308:

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.

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?
When Excel opens a specially crafted Excel file that results from the processing of malformed FNGROUPCOUNT value file, 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 a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message 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. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
Top of sectionTop of section
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Microsoft Excel Malformed LABEL record Vulnerability - CVE-2006-1309

A remote code execution vulnerability exists in Excel that results from the processing of a malformed LABEL record file. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

Mitigating Factors for Microsoft Malformed LABEL record Vulnerability - CVE-2006-1309:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Excel Malformed LABEL record Vulnerability - CVE-2006-1309:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.

This vulnerability could be exploited when a user opens a file.
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FAQ for Microsoft Excel Malformed LABEL record Vulnerability - CVE-2006-1309:

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.

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?
When Excel opens a specially crafted Excel file that results from the processing of a malformed LABEL record file, 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 a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message 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. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
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Microsoft Excel Rebuilding Vulnerability - CVE-2006-2388

A remote code execution vulnerability exists in Excel that results from the processing of a malformed Chart file. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

Mitigating Factors for Microsoft Excel Rebuilding Vulnerability - CVE-2006-2388:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Excel Rebuilding Vulnerability - CVE-2006-2388:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.

This vulnerability could be exploited when a user opens a file.
Top of sectionTop of section

FAQ for Microsoft Excel Rebuilding Vulnerability - CVE-2006-2388:

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.

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?
When Excel opens a specially crafted Excel file that results from the processing of a malformed file, 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 a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message 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. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued. This security bulletin addresses the privately disclosed vulnerability as well as additional issues discovered through internal investigations.

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.
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Microsoft Excel Malformed file Vulnerability - CVE-2006-3059

A remote code execution vulnerability exists in Excel that results from the processing of a malformed file. An attacker could exploit the vulnerability by constructing a specially crafted Excel file that could allow remote code execution.

Mitigating Factors for Microsoft Excel Using a Malformed file Vulnerability - CVE-2006-3059:

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.

On Outlook 2002 and Outlook 2003, the vulnerability could not be exploited automatically through e-mail. For an attack to be successful a user must accept a prompt confirming that they Open, Save or Cancel the attachment that is sent in an e-mail message before the exploit could occur.

In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site.

Note Office 2000 does not prompt the user to Open, Save, or Cancel before opening a document.
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Workarounds for Microsoft Malformed file Vulnerability - CVE-2006-3059:

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.

Do not open or save Microsoft Excel files that you receive from un-trusted sources or that you receive unexpectedly from trusted sources.

This vulnerability could be exploited when a user opens a file.
Top of sectionTop of section

FAQ for Microsoft Excel Malformed file Vulnerability - CVE-2006-3059:

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.

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?
When Excel opens a specially crafted malformed Excel file, 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 a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted 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 instant messenger message that takes users to the attacker's Web site

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.

What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who have sufficient administrative permissions are given the ability 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 validates the length of a record before it passes the message to the allocated buffer.

When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. While the initial report was provided through responsible disclosure, the vulnerability was later disclosed publicly. This security bulletin addresses the publicly disclosed vulnerability as well as additional issues discovered through internal investigations.

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.

Disclaimer:

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions:

V1.0 (July 11, 2006): Bulletin published.