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1 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 1 of 28 TechNet Home > TechNet Security > Bulletins Microsoft Security Bulletin MS Vulnerabilities in FTP Service for Internet Services Could Allow Remote Code Execution (975254) Published: October 13, 2009 Version: 1.0 General Executive Summary This security update resolves two publicly disclosed vulnerabilities in the FTP Service in Microsoft Internet Services (IIS) 5.0, Microsoft Internet Services (IIS) 5.1, Microsoft Internet Services (IIS) 6.0, and Microsoft Internet Services (IIS) 7.0. On IIS 7.0, only FTP Service 6.0 is affected. The vulnerabilities could allow remote code execution (RCE) on systems running FTP Service on IIS 5.0, or denial of service (DoS) on systems running FTP Service on IIS 5.0, IIS 5.1, IIS 6.0 or IIS 7.0. This security update is rated for IIS 5.0; IIS 5.1; IIS 6.0; and FTP Service 6.0 on IIS 7.0. For more information, see the subsection, Affected and Non-Affected Software, in this section. The security update addresses the vulnerabilities by modifying the way that the FTP Service handles list operations. For more information about the vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability. This security update also addresses the vulnerability first described in Microsoft Security Advisory Recommendation. The majority of customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates and install this update manually. For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update at the earliest opportunity using update management software, or by checking for updates using the Microsoft Update service. See also the section, Detection and Deployment Tools and Guidance, later in this bulletin. Known Issues. Microsoft Knowledge Base Article documents the currently known issues that customers may experience when installing this security update. The article also documents recommended solutions for these issues. Affected and Non-Affected Software The following software have been tested to determine which versions or editions are affected. Other versions or editions are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, visit Microsoft Support Lifecycle. Affected Software Operating System Component Maximum Security Impact IIS 5.0 (FTP Service 5.0) Aggregate Severity Rating Bulletins Replaced by this Update

2 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 2 of 28 Microsoft Windows 2000 Service Pack 4 Microsoft Internet Services 5.0 Remote Code Execution None IIS 5.1 (FTP Service 5.1) Windows XP Service Pack 2 and Windows XP Service Pack 3 Microsoft Internet Services 5.1 Denial of Service None Windows XP Professional x64 Edition Service Pack 2 Microsoft Internet Services 5.1 Denial of Service None IIS 6.0 (FTP Service 6.0) Windows Server 2003 Service Pack 2 Microsoft Internet Services 6.0 Denial of Service None Windows Server 2003 x64 Edition Service Pack 2 Microsoft Internet Services 6.0 Denial of Service None Windows Server 2003 with SP2 for Itanium-based Systems Microsoft Internet Services 6.0 Denial of Service None IIS 7.0 (FTP Service 6.0) Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2 Microsoft Internet Services 7.0 Denial of Service None Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2 Microsoft Internet Services 7.0 Denial of Service None Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2* Microsoft Internet Services 7.0 Denial of Service None Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2* Microsoft Internet Services 7.0 Denial of Service None Windows Server 2008 for Itaniumbased Systems and Windows Server Microsoft Internet Services 7.0 Denial of Service None

3 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 3 of for Itaniumbased Systems Service Pack 2 *Server Core installation affected. This update applies, with the same severity rating, to supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, whether or not installed using the Server Core installation option. For more information on this installation option, see the MSDN articles, Server Core and Server Core for Windows Server 2008 R2. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008 and Windows Server 2008 R2; see Compare Server Core Installation Options. Non-Affected Software Operating System Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2 Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2 Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2 Windows 7 for 32-bit Systems Windows 7 for x64-based Systems Windows Server 2008 R2 for x64-based Systems Windows Server 2008 R2 for Itanium-based Systems Component Microsoft Internet Services 7.0 (FTP Service 7.5*) Microsoft Internet Services 7.0 (FTP Service 7.5*) Microsoft Internet Services 7.0 (FTP Service 7.5*) Microsoft Internet Services 7.0 (FTP Service 7.5*) Microsoft Internet Services 7.5 (FTP Service 7.5) Microsoft Internet Services 7.5 (FTP Service 7.5) Microsoft Internet Services 7.5 (FTP Service 7.5) Microsoft Internet Services 7.5 (FTP Service 7.5) *Available as an out-of-box download. See entry in Frequently Asked Questions. Frequently Asked Questions (FAQ) Related to This Security Update Where are the file information details? Refer to the reference tables in the Security Update Deployment section for the location of the file information details. Why does this update address several reported security vulnerabilities? This update contains support 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 need to install this update only. I installed FTP using Windows Server 2008 Server Manager. Is my system affected? When you use Windows Server 2008 Server Manager to install FTP, you are installing FTP Service 6.0, which is affected. Microsoft recommends that you install the appropriate security update from this bulletin or upgrade to FTP Service 7.5. Is FTP Service 7.5 for Windows Vista or Windows Server 2008 affected by this vulnerability? No. FTP Service 7.5, available as an out-of-box download for 32-bit and x64-based versions of Windows Vista and Windows Server 2008, is not affected by this vulnerability. See the following sites on Download Center:

4 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 4 of 28 Microsoft FTP Service 7.5 for IIS 7.0 (x86) Microsoft FTP Service 7.5 for IIS 7.0 (x64) I am using an older release of the software discussed in this security bulletin. What should I do? The affected software listed in this bulletin have been tested to determine which releases are affected. Other releases are past their support life cycle. To determine the support life cycle for your software release, visit Microsoft Support Lifecycle. It should be a priority for customers who have older releases of the software to migrate to supported releases to prevent potential exposure to vulnerabilities. For more information about the Windows Product Lifecycle, visit Microsoft Support Lifecycle. For more information about the extended security update support period for these software versions or editions, visit Microsoft Product Support Services. Customers who require custom support for older releases must contact their Microsoft account team representative, their Technical Account Manager, or the appropriate Microsoft partner representative for custom support options. Customers without an Alliance, Premier, or Authorized Contract can contact their local Microsoft sales office. For contact information, visit Microsoft Worldwide, select the country, and then click Go to see a list of telephone numbers. When you call, ask to speak with the local Premier Support sales manager. For more information, see the Windows Operating System Product Support Lifecycle FAQ. Vulnerability Severity Ratings and Vulnerability Identifiers The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the October bulletin summary. For more information, see Microsoft Exploitability Index. Vulnerability Severity Rating and Maximum Security Impact by Affected Software Affected Software IIS FTP Service DoS Vulnerability - CVE IIS FTP Service RCE and DoS Vulnerability - CVE Aggregate Severity Rating IIS 5.0 (FTP Service 5.0) Microsoft Internet Services 5.0 on Microsoft Windows 2000 Service Pack 4 Denial of Service Remote Code Execution IIS 5.1 (FTP Service 5.1) Microsoft Internet Services 5.1 on Windows XP Service Pack 2 and Windows XP Service Pack 3 Denial of Service Denial of Service IIS 6.0 (FTP Service 6.0) Microsoft Internet Services 6.0 on Windows Server 2003 Service Pack 2 Denial of Service Denial of Service Microsoft Internet Services 6.0 on Windows Server 2003 x64 Edition Service Pack 2 Denial of Service Denial of Service Microsoft Internet Services 6.0 on Denial of Service Denial of Service

5 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 5 of 28 Windows Server 2003 with SP2 for Itanium-based Systems IIS 7.0 (FTP Service 6.0) Microsoft Internet Services 7.0 on Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2 Denial of Service Not applicable Microsoft Internet Services 7.0 on Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2 Denial of Service Not applicable Microsoft Internet Services 7.0 on Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2* Denial of Service Not applicable Microsoft Internet Services 7.0 on Windows Server 2008 for x64-based bit Systems and Windows Server 2008 for x64-based Systems Service Pack 2* Denial of Service Not applicable Microsoft Internet Services 7.0 on Windows Server 2008 for Itaniumbased Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2 Denial of Service Not applicable *Server Core installation affected. This update applies, with the same severity rating, to supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, whether or not installed using the Server Core installation option. For more information on this installation option, see the MSDN articles, Server Core and Server Core for Windows Server 2008 R2. Note that the Server Core installation option does not apply to certain editions of Windows Server 2008 and Windows Server 2008 R2; see Compare Server Core Installation Options. IIS FTP Service DoS Vulnerability - CVE A vulnerability exists in the FTP Service in Microsoft Internet Services (IIS) 5.0, Microsoft Internet Services (IIS) 5.1, Microsoft Internet Services (IIS) 6.0, and Microsoft Internet Services (IIS) 7.0. The vulnerability could allow denial of service (DoS). To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE Mitigating Factors for IIS FTP Service DoS Vulnerability - CVE Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors may be helpful in your situation: FTP Service is not installed by default on all supported editions of Microsoft Windows 2000, Windows XP, Windows Vista, Windows Server 2003 Windows Server 2008 and Windows 7. Workarounds for IIS FTP Service DoS Vulnerability - CVE Workaround refers to a setting or configuration change that does not correct the underlying

6 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 6 of 28 vulnerability but would help block known attack vectors before you apply the update. Microsoft has tested the following workarounds and states in the discussion whether a workaround reduces functionality: Disable the FTP service Disable the FTP service using one of the following procedures: From the command prompt, enter the following command: net stop msftpsvc In the Internet Services panel, perform the following steps: 1. Expand your server and right click on the FTP site. 2. Click Stop. Impact of workaround. You will not be able to transfer files using the FTP service. How to undo the workaround. Re-enable the FTP service using one of the following procedures: From the command prompt, enter the following command: net start msftpsvc In the Internet Services panel, perform the following steps: 1. Expand your server and right click on the FTP site. 2. Click Start. Deny FTP write access to anonymous users This workaround blocks denial of service attacks from anonymous users. This workaround blocks known exploits and minimizes the impact of any variations of this attack vector. However, this workaround does not render the vulnerability completely inaccessible to exploitation. Anonymous users are not granted FTP write access by default. If anonymous write access has been granted on an FTP server, the administrator can modify IIS permissions to prevent anonymous write access. Anonymous users will not be able to cause a remote code execution with this workaround. To modify IIS permissions to prevent FTP write access to anonymous users, perform the following steps: 1. Launch IIS Manager. 2. Right-click Default FTP Site and point to Properties. 3. Click the Home Directory tab. 4. Ensure that Write is deselected. Impact of workaround: Anonymous users will not have the ability to publish content on the server using the FTP Service. How to undo the workaround. 1. Launch IIS Manager. 2. Right-click Default FTP Site and point to Properties. 3. Click the Home Directory tab. 4. Ensure that Write is selected. Deny FTP access to anonymous users This workaround blocks denial of service attacks from unauthenticated users without a valid user

7 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 7 of 28 account. This workaround blocks known exploits and minimizes the impact of any variations of this attack vector. However, this workaround does not render the vulnerability completely inaccessible to exploitation. Anonymous users are not granted FTP write access by default. If anonymous write access has been granted on an FTP server, the administrator can modify IIS permissions to prevent anonymous write access. Anonymous users will not be able to exploit the vulnerability with this workaround. To modify IIS permissions to prevent FTP write access to anonymous users, perform the following steps: 1. Launch IIS Manager. 2. Right click Default FTP Site and point to Properties. 3. Click the SecurityAccounts tab. 4. Ensure that Allow anonymous connections is deselected. Impact of Workaround: Anonymous users will not have access to the FTP Service. How to undo the workaround. 1. Launch IIS Manager. 2. Right click Default FTP Site and point to Properties. 3. Click the SecurityAccounts tab. 4. Ensure that Allow anonymous connections is selected. Modify NTFS file system permissions to disallow directory creation by FTP users This workaround blocks denial of service attacks from authenticated users. This workaround blocks known exploits and minimizes the impact of any variations of this attack vector. However, this workaround does not render the vulnerability completely inaccessible to exploitation. An administrator can modify NTFS file system permissions on the root directories of FTP sites hosted on a server to disallow creation of directories by FTP users. This modification still allows FTP users to upload files to existing directories. Authenticated and unauthenticated users will not be able to cause a remote code execution with this workaround. As administrator, perform the following steps to remove directory creation privileges from the Users group. If you have a configured FTP user or custom group to manage your FTP users, replace the Users group in Step 5 below with these custom identities. 1. Browse to the root directory of your FTP site. By default this is in %systemroot% \inetpub\ftproot. 2. Right-click the directory and select Properties. 3. Click the Security tab and click Advanced. 4. Click Change Permissions. 5. Select the Users group and click Edit. 6. Deselect Create Folders/Append Data. Impact of Workaround: FTP users will not be able to create directories through the FTP Service. FTP users will still be able to upload files to existing directories through the FTP Service. Upgrade to FTP Service 7.5 FTP Service 7.5 is available for Internet Services 7.0. This version of FTP Service is not affected by the vulnerabilities described in this bulletin. See the following sites on Download

8 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 8 of 28 Center: Microsoft FTP Service 7.5 for IIS 7.0 (x86) Microsoft FTP Service 7.5 for IIS 7.0 (x64) Impact of workaround: FTP sites will need to be migrated from FTP Service 6.0 to FTP Service 7.5. FAQ for IIS FTP Service DoS Vulnerability - CVE What is the scope of the vulnerability? This is a denial of service vulnerability. An attacker who exploited this vulnerability could cause the affected service to stop responding and automatically restart. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate their user rights, but it could cause the affected system to stop accepting requests. What causes the vulnerability? This vulnerability is caused by the way that the Microsoft FTP service in IIS handles list commands. What might an attacker use the vulnerability to do? An attacker who successfully exploited this vulnerability could a user s system to become nonresponsive and restart. How could an attacker exploit the vulnerability? An attacker could exploit this vulnerability by sending specially crafted list commands to the server. What systems are primarily at risk from the vulnerability? Server systems running Microsoft File Transfer Protocol Service (FTP). What does the update do? This update modifies the way that the Microsoft FTP server handles list command operations. When this security bulletin was issued, had this vulnerability been publicly disclosed?. This vulnerability has been publicly disclosed. It has been assigned Common Vulnerability and Exposure number CVE When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?. Microsoft is aware of limited, targeted attacks attempting to exploit the vulnerability. Does applying this security update help protect customers from the code, published publicly, that attempts to exploit this vulnerability?. 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 IIS FTP Service RCE and DoS Vulnerability - CVE A Vulnerability exists in the FTP Service in Microsoft Internet Services (IIS) 5.0, Microsoft Internet Services (IIS) 5.1, and Microsoft Internet Services (IIS) 6.0. The vulnerability could allow remote code execution (RCE) on systems running FTP Service on IIS 5.0, or denial of service (DoS) on systems running FTP Service on IIS 5.1, IIS 6.0. To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE Mitigating Factors for IIS FTP Service RCE and DoS Vulnerability - CVE Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors may be helpful in your situation: FTP Service is not installed by default on all supported editions of Microsoft Windows 2000, Windows XP, Windows Vista, Windows Server 2003, Windows Server 2008 and Windows 7. Internet Services 5.1 on Window XP and Internet Services 6.0 on

9 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service for...page 9 of 28 Windows Server 2003 are at reduced risk because these versions were compiled using the /GS compiler option. This does not remove the vulnerability but does make exploitation of the vulnerability more difficult and reduces the impact to a denial of service. Internet Services 7.0 is not affected by this vulnerability. Workarounds for IIS FTP Service RCE and DoS Vulnerability - CVE Workaround refers to a setting or configuration change that does not correct the underlying vulnerability but would help block known attack vectors before you apply the update. Microsoft has tested the following workarounds and states in the discussion whether a workaround reduces functionality: Disable the FTP service Disable the FTP service using one of the following procedures: From the command prompt, enter the following command: net stop msftpsvc In the Internet Services panel, perform the following steps: 1. Expand your server and right click on the FTP site. 2. Click Stop. Impact of workaround. You will not be able to transfer files using the FTP service. How to undo the workaround. Re-enable the FTP service using one of the following procedures: From the command prompt, enter the following command: net start msftpsvc In the Internet Services panel, perform the following steps: 1. Expand your server and right click on the FTP site. 2. Click Start. Deny FTP write access to anonymous users This workaround blocks remote code execution attacks from anonymous users. With this workaround, all affected versions of IIS are still vulnerable to denial of service attacks from anonymous users. This workaround blocks known exploits and minimizes the impact of any variations of this attack vector. However, this workaround does not render the vulnerability completely inaccessible to exploitation. Anonymous users are not granted FTP write access by default. If anonymous write access has been granted on an FTP server, the administrator can modify IIS permissions to prevent anonymous write access. Anonymous users will not be able to cause a remote code execution with this workaround. To modify IIS permissions to prevent FTP write access to anonymous users, perform the following steps: 1. Launch IIS Manager. 2. Right-click Default FTP Site and point to Properties. 3. Click the Home Directory tab. 4. Ensure that Write is deselected. Impact of workaround: Anonymous users will not have the ability to publish content on the server using the FTP Service.

10 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 10 of 28 How to undo the workaround. 1. Launch IIS Manager. 2. Right-click Default FTP Site and point to Properties. 3. Click the Home Directory tab. 4. Ensure that Write is selected. Deny FTP access to anonymous users This workaround blocks denial of service attacks from unauthenticated users without a valid user account. This workaround blocks known exploits and minimizes the impact of any variations of this attack vector. However, this workaround does not render the vulnerability completely inaccessible to exploitation. Anonymous users are not granted FTP write access by default. If anonymous write access has been granted on an FTP server, the administrator can modify IIS permissions to prevent anonymous write access. Anonymous users will not be able to exploit the vulnerability with this workaround. To modify IIS permissions to prevent FTP write access to anonymous users, perform the following steps: 1. Launch IIS Manager. 2. Right click Default FTP Site and point to Properties. 3. Click the SecurityAccounts tab. 4. Ensure that Allow anonymous connections is deselected. Impact of Workaround: Anonymous users will not have access to the FTP Service. How to undo the workaround. 1. Launch IIS Manager. 2. Right click Default FTP Site and point to Properties. 3. Click the SecurityAccounts tab. 4. Ensure that Allow anonymous connections is selected. Modify NTFS file system permissions to disallow directory creation by FTP users This workaround blocks remote code execution attacks from authenticated users. With this workaround, all affected versions of IIS server are still vulnerable to denial of service attacks from authenticated users. This workaround blocks known exploits and minimizes the impact of any variations of this attack vector. However, this workaround does not render the vulnerability completely inaccessible to exploitation. An administrator can modify NTFS file system permissions on the root directories of FTP sites hosted on a server to disallow creation of directories by FTP users. This modification still allows FTP users to upload files to existing directories. Authenticated and unauthenticated users will not be able to cause a remote code execution with this workaround. As administrator, perform the following steps to remove directory creation privileges from the Users group. If you have a configured FTP user or custom group to manage your FTP users, replace the Users group in Step 5 below with these custom identities. 1. Browse to the root directory of your FTP site. By default this is in %systemroot% \inetpub\ftproot. 2. Right-click the directory and select Properties.

11 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 11 of Click the Security tab and click Advanced. 4. Click Change Permissions. 5. Select the Users group and click Edit. 6. Deselect Create Folders/Append Data. Impact of Workaround: FTP users will not be able to create directories through the FTP Service. FTP users will still be able to upload files to existing directories through the FTP Service. How to undo the workaround. 1. Browse to the root directory of your FTP site. By default this is in %systemroot% \inetpub\ftproot. 2. Right-click the directory and select Properties. 3. Click the Security tab and click Advanced. 4. Click Change Permissions. 5. Select the Users group and click Edit. 6. Select Create Folders/Append Data. Upgrade to FTP Service 7.5 FTP Service 7.5 is available for Internet Services 7.0. This version of FTP Service is not affected by the vulnerabilities described in this bulletin. See the following sites on Download Center: Microsoft FTP Service 7.5 for IIS 7.0 (x86) Microsoft FTP Service 7.5 for IIS 7.0 (x64) Impact of workaround: FTP sites will need to be migrated from FTP Service 6.0 to FTP Service 7.5. FAQ for IIS FTP Service RCE and DoS Vulnerability - CVE What is the scope of the vulnerability? This is a denial of service vulnerability. An attacker who exploited this vulnerability could cause the affected service to stop responding and automatically restart. Note that the denial of service vulnerability would not allow an attacker to execute code or to elevate their user rights, but it could cause the affected system to stop accepting requests. This is a remote code execution vulnerability on systems running Microsoft Windows 2000 Service Pack 4 and a denial of service vulnerability on all of the other affected platforms. An attacker who successfully exploited this vulnerability in IIS 5.0 on Microsoft Windows 2000 Service Pack 4 could cause remote code execution in the context of LocalSystem. An attacker who successfully exploited this vulnerability on IIS 5.1 and IIS 6.0 could cause the IIS FTP service to stop and become unresponsive. What causes the vulnerability? This vulnerability is caused by the way that the Microsoft FTP service in IIS handles list commands. What might an attacker use the vulnerability to do? An attacker with access to the FTP Service could use this vulnerability to cause a stack-based overrun that could allow execution of arbitrary code in the context of the LocalSystem account on systems running IIS 5.0, or denial of service on affected systems running IIS 5.1 or IIS 6.0. In configurations of FTP Service where anonymous authentication is allowed, the attacker need not be authenticated for exploitation to occur. For more information on the LocalSystem account, see the MSDN article, LocalSystem Account. How could an attacker exploit the vulnerability? An anonymous or authenticated user with access to the FTP service could send FTP NLST commands causing memory corruption and remote code execution on systems running IIS 5.0 on Microsoft Windows 2000 and denial of service on systems running IIS 5.1 or IIS 6.0 on other platforms.

12 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 12 of 28 What systems are primarily at risk from the vulnerability? Server systems running Microsoft File Transfer Protocol Service (FTP). What does the update do? This update modifies the way that the Microsoft FTP server handles list command operations. When this security bulletin was issued, had this vulnerability been publicly disclosed?. This vulnerability has been publicly disclosed. It has been assigned Common Vulnerability and Exposure number CVE When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?. Microsoft is aware of limited, targeted attacks attempting to exploit the vulnerability. Does applying this security update help protect customers from the code, published publicly, that attempts to exploit this vulnerability?. 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 Update Detection and Deployment Tools and Guidance Manage the software and security updates you need to deploy to the servers, desktop, and mobile systems in your organization. For more information see the TechNet Update Management Center. The Microsoft TechNet Security Web site provides additional information about security in Microsoft products. Security updates are available from Microsoft Update and Windows Update. Security updates are also available from the Microsoft Download Center. You can find them most easily by doing a keyword search for "security update." Finally, security updates can be downloaded from the Microsoft Update Catalog. The Microsoft Update Catalog provides a searchable catalog of content made available through Windows Update and Microsoft Update, including security updates, drivers and service packs. By searching using the security bulletin number (such as, "MS07-036"), you can add all of the applicable updates to your basket (including different languages for an update), and download to the folder of your choosing. For more information about the Microsoft Update Catalog, see the Microsoft Update Catalog FAQ. Note Microsoft discontinued support for Office Update and the Office Update Inventory Tool as of August 1, To continue getting the latest updates for Microsoft Office products, use Microsoft Update. For more information, see About Microsoft Office Update: Frequently Asked Questions. Detection and Deployment Guidance Microsoft provides detection and deployment guidance for security updates. This guidance contains recommendations and information that can help IT professionals understand how to use various tools for detection and deployment of security updates. For more information, see Microsoft Knowledge Base Article Microsoft Baseline Security Analyzer Microsoft Baseline Security Analyzer (MBSA) allows administrators to scan local and remote systems for missing security updates as well as common security misconfigurations. For more information about MBSA, visit Microsoft Baseline Security Analyzer. The following table provides the MBSA detection summary for this security update. Software MBSA 2.1 Microsoft Windows 2000 Service Pack 4 Windows XP Service Pack 2 and Windows XP Service Pack 3 Windows XP Professional x64 Edition Service Pack 2

13 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 13 of 28 Windows Server 2003 Service Pack 2 Windows Server 2003 x64 Edition Service Pack 2 Windows Server 2003 with SP2 for Itanium-based Systems Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2 Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2 Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2 Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2 For more information about MBSA 2.1, see MBSA 2.1 Frequently Asked Questions. Windows Server Update Services By using Windows Server Update Services (WSUS), administrators can deploy the latest critical updates and security updates for Windows 2000 operating systems and later, Office XP and later, Exchange Server 2003, and SQL Server For more information about how to deploy this security update using Windows Server Update Services, visit the Windows Server Update Services Web site. Systems Management Server The following table provides the SMS detection and deployment summary for this security update. Software SMS 2.0 SMS 2003 with SUIT SMS 2003 with ITMU Configuration Manager 2007 Microsoft Windows 2000 Service Pack 4 Windows XP Service Pack 2 and Windows XP Service Pack 3 Windows XP Professional x64 Edition Service Pack 2 No No Windows Server 2003 Service Pack 2 Windows Server 2003 x64 Edition Service Pack 2 Windows Server 2003 with SP2 for Itanium-based Systems No No No No Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2 Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2 No No See Note for Windows Vista and Windows Server 2008 below No No See Note for Windows Vista and Windows Server 2008 below

14 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 14 of 28 Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2 Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2 Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2 No No See Note for Windows Vista and Windows Server 2008 below No No See Note for Windows Vista and Windows Server 2008 below No No See Note for Windows Vista and Windows Server 2008 below For SMS 2.0 and SMS 2003, the Security Update Inventory Tool (SUIT) can be used by SMS to detect security updates. See also Downloads for Systems Management Server 2.0. For SMS 2003, the SMS 2003 Inventory Tool for Microsoft Updates (ITMU) 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 ITMU, see SMS 2003 Inventory Tool for Microsoft Updates. For more information about SMS scanning tools, see SMS 2003 Software Update Scanning Tools. See also Downloads for Systems Management Server System Center Configuration Manager 2007 uses WSUS 3.0 for detection of updates. For more information about Configuration Manager 2007 Software Update Management, visit System Center Configuration Manager Note for Windows Vista and Windows Server 2008 Microsoft Systems Management Server 2003 with Service Pack 3 includes support for Windows Vista and Windows Server 2008 manageability. For more information about SMS, visit the SMS Web site. For more detailed information, see Microsoft Knowledge Base Article : Summary list of monthly detection and deployment guidance articles. Update Compatibility Evaluator and Application Compatibility Toolkit Updates often write to the same files and registry settings required for your applications to run. This can trigger incompatibilities and increase the time it takes to deploy security updates. You can streamline testing and validating Windows updates against installed applications with the Update Compatibility Evaluator components included with Application Compatibility Toolkit. The Application Compatibility Toolkit (ACT) contains the necessary tools and documentation to evaluate and mitigate application compatibility issues before deploying Microsoft Windows Vista, a Windows Update, a Microsoft Security Update, or a new version of Windows Internet Explorer in your environment. Security Update Deployment Affected Software For information about the specific security update for your affected software, click the appropriate link: Windows 2000 (all editions) Reference Table The following table contains the security update information for this software. You can find additional information in the subsection, Deployment, in this section.

15 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 15 of 28 Inclusion in Future Service Packs The update for this issue may be included in a future update rollup Deployment Installing without user intervention Installing without restarting Update log file Further information Windows2000-kb x86-enu /quiet Windows2000-kb x86-enu /norestart kb log See the subsection, Detection and Deployment Tools and Guidance Restart Requirement Restart required? HotPatching Removal File Registry Key Verification, you must restart your system after you apply this security update Not applicable Use Add or Remove Programs tool in Control Panel or the Spuninst.exe utility located in the %Windir%\$NTUninstallKB $\Spuninst folder See Microsoft Knowledge Base Article HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows 2000 \SP5\KB975254\Filelist Deployment Installing the Update When you install this security update, the installer checks whether one or more of the files that are being updated on your system have previously been updated by a Microsoft hotfix. If you have previously installed a hotfix to update one of these files, the installer copies the RTMQFE, SP1QFE, or SP2QFE files to your system. Otherwise, the installer copies the RTMGDR, SP1GDR, or SP2GDR files to your system. Security updates may not contain all variations of these files. For more information about this behavior, see Microsoft Knowledge Base Article For more information about the installer, visit the Microsoft TechNet Web site. For more information about the terminology that appears in this bulletin, such as hotfix, see Microsoft Knowledge Base Article This security update supports the following setup switches. Supported Security Update Installation Switches Switch /help Description Displays the command-line options. Setup Modes /passive Unattended Setup mode. No user interaction is required, but installation status is displayed. If a restart is required at the end of Setup, a dialog box will be presented to the user with a timer warning that the computer will restart in

16 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 16 of seconds. /quiet Quiet mode. This is the same as unattended mode, but no status or error messages are displayed. Restart Options /norestart /forcerestart /warnrestart[:x] /promptrestart Does not restart when installation has completed. Restarts the computer after installation and force other applications to close at shutdown without saving open files first. Presents a dialog box with a timer warning the user that the computer will restart in x seconds. (The default setting is 30 seconds.) Intended for use with the /quiet switch or the /passive switch. Displays a dialog box prompting the local user to allow a restart. Special Options /overwriteoem /nobackup /forceappsclose /log:path /extract[:path] /ER Overwrites OEM files without prompting. Does not back up files needed for uninstall. Forces other programs to close when the computer shuts down. Allows the redirection of installation log files. Extracts files without starting the Setup program. Enables extended error reporting. /verbose Enables verbose logging. During installation, creates % Windir%\CabBuild.log. This log details the files that are copied. Using this switch may cause the installation to proceed more slowly. Note You can combine these switches into one command. For backward compatibility, the security update also supports the setup switches that the earlier version of the Setup program uses. For more information about the supported installation switches, see Microsoft Knowledge Base Article Removing the Update This security update supports the following setup switches. Supported Spuninst.exe Switches Switch /help Description Displays the command-line options. Setup Modes /passive /quiet Unattended Setup mode. No user interaction is required, but installation status is displayed. If a restart is required at the end of Setup, a dialog box will be presented to the user with a timer warning that the computer will restart in 30 seconds. Quiet mode. This is the same as unattended mode, but no status or error messages are displayed. Restart Options

17 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 17 of 28 /norestart /forcerestart /warnrestart[:x] /promptrestart Does not restart when installation has completed. Restarts the computer after installation and force other applications to close at shutdown without saving open files first. Presents a dialog box with a timer warning the user that the computer will restart in x seconds. (The default setting is 30 seconds.) Intended for use with the /quiet switch or the /passive switch. Displays a dialog box prompting the local user to allow a restart. Special Options /forceappsclose /log:path Forces other programs to close when the computer shuts down. Allows the redirection of installation log files. Verifying That the Update Has Been Applied Microsoft Baseline Security Analyzer To verify that a security update has been applied to an affected system, you may be able to use the Microsoft Baseline Security Analyzer (MBSA) tool. See the section, Detection and Deployment Tools and Guidance, earlier in this bulletin for more information. File Version Verification Because there are several editions of Microsoft Windows, the following steps may be different on your system. If they are, see your product documentation to complete these steps. 1. Click Start, and then click Search. 2. In the Search Results pane, click All files and folders under Search Companion. 3. In the All or part of the file name box, type a file name from the appropriate file information table, and then click Search. 4. In the list of files, right-click a file name from the appropriate file information table, and then click Properties. Note Depending on the edition of the operating system, or the programs that are installed on your system, some of the files that are listed in the file information table may not be installed. 5. On the Version tab, determine the version of the file that is installed on your system by comparing it to the version that is documented in the appropriate file information table. Note Attributes other than the file version may change during installation. Comparing other file attributes to the information in the file information table is not a supported method of verifying that the update has been applied. Also, in certain cases, files may be renamed during installation. If the file or version information is not present, use one of the other available methods to verify update installation. Registry Key Verification You may also be able to verify the files that this security update has installed by reviewing the registry keys listed in the Reference Table in this section. These registry keys may not contain a complete list of installed files. Also, these registry keys may not be created correctly when an administrator or an OEM integrates or slipstreams this security update into the Windows installation source files.

18 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 18 of 28 Windows XP (all editions) Reference Table The following table contains the security update information for this software. You can find additional information in the subsection, Deployment, in this section. Inclusion in Future Service Packs The update for this issue will be included in a future service pack or update rollup Deployment Installing without user intervention For Windows XP Service Pack 2 and Windows XP Service Pack 3: Windowsxp-kb x86-enu /quiet For Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2: WindowsServer2003.WindowsXP-kb x64-enu /quiet Installing without restarting For Windows XP Service Pack 2 and Windows XP Service Pack 3: Windowsxp-kb x86-enu /norestart Update log file KB log For Windows XP Professional x64 Edition and Windows XP Professional x64 Edition Service Pack 2: WindowsServer2003.WindowsXP-kb x64-enu /norestart Further information See the subsection, Detection and Deployment Tools and Guidance Restart Requirement Restart required? HotPatching Removal File Registry Key Verification This update does not require a restart. The installer stops the required services, applies the update, and then restarts the services. However, if the required services cannot be stopped for any reason, or if required files are being used, this update will require a restart. If this behavior occurs, a message appears that advises you to restart. Not applicable Use Add or Remove Programs tool in Control Panel or the Spuninst.exe utility located in the %Windir%\$NTUninstallKB $\Spuninst See Microsoft Knowledge Base Article For all supported 32-bit editions of Windows XP: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP4\KB975254\Filelist For all supported x64-based editions of Windows XP: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP Version 2003\SP3\KB975254\Filelist Note For supported versions of Windows XP Professional x64 Edition, this security update is the same as supported versions of the Windows Server 2003 x64 Edition security update. Deployment Installing the Update When you install this security update, the installer checks whether one or more of the files that

19 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 19 of 28 are being updated on your system have previously been updated by a Microsoft hotfix. If you have previously installed a hotfix to update one of these files, the installer copies the RTMQFE, SP1QFE, or SP2QFE files to your system. Otherwise, the installer copies the RTMGDR, SP1GDR, or SP2GDR files to your system. Security updates may not contain all variations of these files. For more information about this behavior, see Microsoft Knowledge Base Article For more information about the installer, visit the Microsoft TechNet Web site. For more information about the terminology that appears in this bulletin, such as hotfix, see Microsoft Knowledge Base Article This security update supports the following setup switches. Supported Security Update Installation Switches Switch /help Description Displays the command-line options. Setup Modes /passive /quiet Unattended Setup mode. No user interaction is required, but installation status is displayed. If a restart is required at the end of Setup, a dialog box will be presented to the user with a timer warning that the computer will restart in 30 seconds. Quiet mode. This is the same as unattended mode, but no status or error messages are displayed. Restart Options /norestart /forcerestart /warnrestart[:x] /promptrestart Does not restart when installation has completed. Restarts the computer after installation and force other applications to close at shutdown without saving open files first. Presents a dialog box with a timer warning the user that the computer will restart in x seconds. (The default setting is 30 seconds.) Intended for use with the /quiet switch or the /passive switch. Displays a dialog box prompting the local user to allow a restart. Special Options /overwriteoem /nobackup /forceappsclose /log:path /integrate:path /extract[:path] /ER Overwrites OEM files without prompting. Does not back up files needed for uninstall. Forces other programs to close when the computer shuts down. Allows the redirection of installation log files. Integrates the update into the Windows source files. These files are located at the path that is specified in the switch. Extracts files without starting the Setup program. Enables extended error reporting. /verbose Enables verbose logging. During installation, creates % Windir%\CabBuild.log. This log details the files that are copied. Using this switch may cause the installation to proceed more slowly.

20 Microsoft Security Bulletin MS : Vulnerabilities in FTP Service f... Page 20 of 28 Note You can combine these switches into one command. For backward compatibility, the security update also supports the setup switches that the earlier version of the Setup program uses. For more information about the supported installation switches, see Microsoft Knowledge Base Article Removing the Update This security update supports the following setup switches. Supported Spuninst.exe Switches Switch /help Description Displays the command-line options. Setup Modes /passive /quiet Unattended Setup mode. No user interaction is required, but installation status is displayed. If a restart is required at the end of Setup, a dialog box will be presented to the user with a timer warning that the computer will restart in 30 seconds. Quiet mode. This is the same as unattended mode, but no status or error messages are displayed. Restart Options /norestart /forcerestart /warnrestart[:x] /promptrestart Does not restart when installation has completed Restarts the computer after installation and force other applications to close at shutdown without saving open files first. Presents a dialog box with a timer warning the user that the computer will restart in x seconds. (The default setting is 30 seconds.) Intended for use with the /quiet switch or the /passive switch. Displays a dialog box prompting the local user to allow a restart. Special Options /forceappsclose /log:path Forces other programs to close when the computer shuts down. Allows the redirection of installation log files. Verifying That the Update Has Been Applied Microsoft Baseline Security Analyzer To verify that a security update has been applied to an affected system, you may be able to use the Microsoft Baseline Security Analyzer (MBSA) tool. See the section, Detection and Deployment Tools and Guidance, earlier in this bulletin for more information. File Version Verification Because there are several editions of Microsoft Windows, the following steps may be different on your system. If they are, see your product documentation to complete these steps. 1. Click Start, and then click Search. 2. In the Search Results pane, click All files and folders under Search Companion. 3. In the All or part of the file name box, type a file name from the appropriate file information table, and then click Search. In the list of files, right-click a file name from the appropriate file information table, and