SecurityvulnsSECURITYVULNS:DOC:23629Microsoft Security Bulletin MS10-024 - Important Vulnerabilities in Microsoft Exchange and Windows SMTP Service Could Allow Denial of Service (981832)
Microsoft Security Bulletin MS10-024 - Important
Vulnerabilities in Microsoft Exchange and Windows SMTP Service Could Allow Denial of Service (981832)
Published: April 13, 2010 | Updated: April 15, 2010
Version: 1.2
General Information
Executive Summary
This security update resolves one publicly disclosed vulnerability and one privately reported vulnerability in Microsoft Exchange and Windows SMTP Service. The more severe of these vulnerabilities could allow denial of service if an attacker sent a specially crafted DNS response to a computer running the SMTP service. By default, the SMTP component is not installed on Windows Server 2003, Windows Server 2003 x64 Edition, or Windows XP Professional x64 Edition.
This security update is rated Important for all supported editions of Microsoft Windows 2000, Windows XP, and Windows Server 2003; 32-bit and x64-based editions of Windows Server 2008; Windows Server 2008 R2 for x64-based Systems; and Microsoft Exchange Server 2003. This security update is rated Moderate for Microsoft Exchange Server 2000. For more information, see the subsection, Affected and Non-Affected Software, in this section.
The security update addresses the vulnerabilities by correcting the manner in which SMTP parses MX records and the manner in which SMTP allocates memory for interpreting SMTP command responses. For more information about the vulnerabilities, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.
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 294871.
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 981832 documents the currently known issues that customers may experience when installing this security update. The article also documents recommended solutions for these issues.
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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 Maximum Security Impact Aggregate Severity Rating Bulletins Replaced by this Update
Microsoft Windows
Microsoft Windows 2000 Service Pack 4
(KB976323)
Denial of Service
Important
None
Windows XP Service Pack 2 and Windows XP Service Pack 3
(KB976323)
Denial of Service
Important
None
Windows XP Professional x64 Edition Service Pack 2
(KB976323)
Denial of Service
Important
None
Windows Server 2003 Service Pack 2
(KB976323)
Denial of Service
Important
None
Windows Server 2003 x64 Edition Service Pack 2
(KB976323)
Denial of Service
Important
None
Windows Server 2003 with SP2 for Itanium-based Systems
(KB976323)
Denial of Service
Important
None
Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2**
(KB976323)
Denial of Service
Important
None
Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2**
(KB976323)
Denial of Service
Important
None
Windows Server 2008 R2 for x64-based Systems**
(KB976323)
Denial of Service
Important
None
Microsoft Server Software
Microsoft Exchange Server 2000 Service Pack 3
(KB976703)
Information Disclosure
Moderate
None
Microsoft Exchange Server 2003 Service Pack 2
(KB976702)
Denial of Service
Important
None
Microsoft Exchange Server 2007 Service Pack 1 for x64-based Systems
(KB981407)
None
None[1]
None
Microsoft Exchange Server 2007 Service Pack 2 for x64-based Systems
(KB981383)
None
None[1]
None
Microsoft Exchange Server 2010 for x64-based Systems
(KB981401)
None
None[1]
None
**Server Core installation not affected. The vulnerabilities addressed by this update do not affect supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, when 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.
[1]Severity ratings do not apply to this update because the vulnerabilities discussed in this bulletin do not affect this software. However, Microsoft recommends that customers of this software apply this update, which includes a defense-in-depth measure that adds additional source port entropy to DNS transactions initiated by the SMTP service. For more information, see Frequently Asked Questions (FAQ) Related to This Security Update.
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 Itanium-based Systems
Windows 7 for 32-bit Systems
Windows 7 for x64-based Systems
Windows Server 2008 R2 for Itanium-based Systems
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Frequently Asked Questions (FAQ) Related to This Security Update
Why was this security bulletin revised on April 15, 2010?
Microsoft revised this security bulletin to announce a detection change for Microsoft Exchange Server 2000 Service Pack 3. This is a detection change only. The corrected detection offers the security update to affected systems that previously were not offered this security update. There were no changes to the security update files in this bulletin. Customers who have already installed the KB976703 update successfully on these systems do not need to reinstall the 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.
How are the Microsoft Exchange Server 2007 and Microsoft Exchange Server 2010 updates different from the Microsoft Exchange Server 2000 and Microsoft Exchange Server 2003 updates?
With the release of Microsoft Exchange 2007, Microsoft Exchange is moving to a new servicing model. For better understanding of the Microsoft Exchange servicing model, please see the TechNet article, Exchange 2007 Servicing. For questions regarding the new Microsoft Exchange servicing model, please contact Microsoft Help and Support.
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.
Does this update contain any security-related changes to functionality?
Yes. In addition to the changes that are listed in the Vulnerability Information section of this bulletin, this update includes a defense-in-depth change for Microsoft Exchange 2000 Server Service Pack 3 to address an issue with the Chinese character set when using Outlook Web Access (OWA). This issue only affects Exchange 2000 systems. Please note that the update for Microsoft Exchange 2000 Server Service Pack 3 requires, as a prerequisite, the Exchange 2000 Server Post-Service Pack 3 (SP3) Update Rollup. You must install the Update Rollup for Exchange 2000 (KB870540) before you install the defense-in-depth update that is provided with this security bulletin. This update will detect whether the Update Rollup is installed. If the Update Rollup is not installed, you will be directed to the download Web site. For more information, see Microsoft Knowledge Base Article 870540. To download the prerequisite update, see Update Rollup for Exchange 2000 (KB870540).
This update also includes a defense-in-depth change for Microsoft Exchange 2007 and Microsoft Exchange 2010 that adds additional source port entropy to DNS transactions initiated by the SMTP service.
Do I need to apply updates for both Windows and Exchange?
For systems that have Microsoft Exchange installed, both the Exchange and Windows update should be applied. If you have the SMTP service enabled but do not run the Exchange service, only the Windows update need be applied.
I am running Exchange 2007 or Exchange 2010. Why am I being offered an update if they are not affected by the vulnerabilities described in this bulletin?
The updates for Microsoft Exchange 2007 and Microsoft Exchange 2010 only include the defense-in-depth change that adds additional source port entropy to DNS transactions initiated by the SMTP service.
Do I need to install the update rollup package for Exchange Server 2007-based servers in a particular sequence?
Refer to the TechNet article, How to Install the Latest Service Pack or Update Rollup for Exchange 2007.
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. For more information about the product lifecycle, visit the Microsoft Support Lifecycle Web site.
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. To determine the support lifecycle for your software release, see Select a Product for Lifecycle Information. For more information about service packs for these software releases, see Lifecycle Supported Service Packs.
Customers who require custom support for older software 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 the Microsoft Worldwide Information Web site, select the country in the Contact Information list, 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 Microsoft Support Lifecycle Policy FAQ.
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Vulnerability Information
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 April bulletin summary. For more information, see Microsoft Exploitability Index.
Vulnerability Severity Rating and Maximum Security Impact by Affected Software
Affected Software SMTP Server MX Record Vulnerability - CVE-2010-0024 SMTP Memory Allocation Vulnerability - CVE-2010-0025 Aggregate Severity Rating
Microsoft Windows
Microsoft Windows 2000 Service Pack 4
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows XP Service Pack 2 and Windows XP Service Pack 3
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows XP Professional x64 Edition Service Pack 2
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows Server 2003 Service Pack 2
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows Server 2003 x64 Edition Service Pack 2
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows Server 2003 with SP2 for Itanium-based Systems
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2**
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2**
Important
Denial of Service
Moderate
Information Disclosure
Important
Windows Server 2008 R2 for x64-based Systems**
Important
Denial of Service
Moderate
Information Disclosure
Important
Microsoft Server Software
Microsoft Exchange Server 2000 Service Pack 3
Not applicable
Moderate
Information Disclosure
Moderate
Microsoft Exchange Server 2003 Service Pack 2
Important
Denial of Service
Not applicable
Important
Microsoft Exchange Server 2007 Service Pack 1 for x64-based Systems
None[1]
Not applicable
None
Microsoft Exchange Server 2007 Service Pack 2 for x64-based Systems
None[1]
Not applicable
None
Microsoft Exchange Server 2010 for x64-based Systems
None[1]
Not applicable
None
**Server Core installation not affected. The vulnerabilities addressed by this update do not affect supported editions of Windows Server 2008 or Windows Server 2008 R2 as indicated, when 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.
[1]Severity ratings do not apply to this update because the vulnerabilities discussed in this bulletin do not affect this software. However, Microsoft recommends that customers of this software apply this update, which includes a defense-in-depth measure that adds additional source port entropy to DNS transactions initiated by the SMTP service. For more information, see Frequently Asked Questions (FAQ) Related to This Security Update.
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SMTP Server MX Record Vulnerability - CVE-2010-0024
A denial of service vulnerability exists in the way that the Microsoft Windows Simple Mail Transfer Protocol (SMTP) component handles specially crafted DNS Mail Exchanger (MX) resource records. An attempt to exploit the vulnerability would not require authentication, allowing an attacker to exploit the vulnerability by sending a specially crafted network message to a computer running the SMTP service. An attacker who successfully exploited this vulnerability could cause the SMTP service to stop responding until restarted.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2010-0024.
Mitigating Factors for SMTP Server MX Record Vulnerability - CVE-2010-0024
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:
•
By default, the SMTP component is not installed on Windows Server 2003, Windows Server 2003 x64 Edition, or Windows XP Professional x64 Edition.
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Workarounds for SMTP Server MX Record Vulnerability - CVE-2010-0024
Microsoft has not identified any workarounds for this vulnerability.
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FAQ for SMTP Server MX Record Vulnerability - CVE-2010-0024
What is the scope of the vulnerability?
This is a denial of service vulnerability. An attacker who exploited this vulnerability could cause the affected SMTP service to stop responding until the specially crafted message is removed from the queue and the service is manually restarted. 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?
The vulnerability exists because the Microsoft Windows Simple Mail Transfer Protocol (SMTP) component incorrectly parses a specially crafted DNS Mail Exchanger (MX) record.
What is the SMTP Service?
The Simple Mail Transfer Protocol (SMTP) service, which transfers e-mail, is installed as part of E-mail Services or Internet Information Services (IIS). SMTP controls how e-mail is transported and then delivered across the Internet to the destination server. The SMTP service sends and receives e-mail between servers. For more information, see the TechNet article, Simple Mail Transfer Protocol (SMTP) Service.
What is an MX resource record?
The mail exchange (MX) resource record specifies a mail exchange server for a DNS domain name. A mail exchange server is a host that processes and forwards mail for the DNS domain name. Processing the mail means either delivering it to the addressee or passing it to a different type of mail transport. Forwarding the mail means sending it to its final destination server, sending it using Simple Mail Transfer Protocol (SMTP) to another mail exchange server that is closer to the final destination, or queuing it for a specified amount of time. For more information on MX Resource Records, see the TechNet article, Resource Record Types.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could cause the SMTP service to stop responding until the specially crafted message is removed from the queue and the service is manually restarted.
How could an attacker exploit the vulnerability?
An attacker could try to exploit the vulnerability by creating a malicious DNS server that returns a specially crafted response to an MX resource record query.
What systems are primarily at risk from the vulnerability?
All operating systems that use the native SMTP component, which is provided as part of the operating system, are at risk from this vulnerability.
What does the update do?
The security update addresses the vulnerability by correcting the manner in which the SMTP service parses MX records.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. This vulnerability has been publicly disclosed. It has been assigned Common Vulnerability and Exposure number CVE-2010-0024.
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 when this security bulletin was originally issued.
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SMTP Memory Allocation Vulnerability - CVE-2010-0025
An information disclosure vulnerability exists in the Microsoft Windows Simple Mail Transfer Protocol (SMTP) component due to the manner in which the SMTP component handles memory allocation. An attacker could exploit the vulnerability by sending invalid commands, followed by the STARTTLS command, to an affected server. An attacker who successfully exploited this vulnerability could read random e-mail message fragments stored on the affected server. Note that this vulnerability would not allow an attacker to execute code or to elevate their user rights directly, but it could be used to produce useful information that could be used to try to further compromise the affected system.
To view this vulnerability as a standard entry in the Common Vulnerabilities and Exposures list, see CVE-2010-0025.
Mitigating Factors for SMTP Memory Allocation Vulnerability - CVE-2010-0025
Microsoft has not identified any mitigating factors for this vulnerability.
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Workarounds for SMTP Memory Allocation Vulnerability - CVE-2010-0025
Microsoft has not identified any workarounds for this vulnerability.
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FAQ for SMTP Memory Allocation Vulnerability - CVE-2010-0025
What is the scope of the vulnerability?
This is an information disclosure vulnerability. An attacker who successfully exploited this vulnerability could read random e-mail message fragments stored on the affected server. Note that this vulnerability would not allow an attacker to execute code or to elevate their user rights directly, but it could be used to produce useful information that could be used to try to further compromise the affected system.
What causes the vulnerability?
The vulnerability exists because the Microsoft Windows Simple Mail Transfer Protocol (SMTP) component improperly allocates memory when interpreting SMTP command responses.
What is the SMTP Service?
The Simple Mail Transfer Protocol (SMTP) service, which transfers e-mail, is installed as part of E-mail Services or Internet Information Services (IIS). SMTP controls how e-mail is transported and then delivered across the Internet to the destination server. The SMTP service sends and receives e-mail between servers. For more information, see the TechNet article, Simple Mail Transfer Protocol (SMTP) Service.
What is the TLS protocol?
The Transport Layer Security (TLS) Handshake Protocol is responsible for the authentication and key exchange necessary to establish or resume secure sessions. When establishing a secure session, the Handshake Protocol manages the following:
•
Cipher suite negotiation
•
Authentication of the server and optionally, the client
•
Session key information exchange
For more information, see the TechNet article, How TLS/SSL Works.
What is SSL?
Secure Sockets Layer (SSL) is a predecessor of the Transport Layer Security protocol. SSL performs the same functions and supports secure network communications using a combination of public and secret key technology. For more information, see the TechNet article, How TLS/SSL Works.
What is the SChannel security package?
The Secure Channel (SChannel) security package is a Security Support Provider (SSP) that implements the Internet standard authentication protocols, Secure Sockets Layer (SSL) and Transport Layer Security (TLS). These components are used to implement secure communications in support of several common Internet and network applications, such as Web browsing. SChannel is part of the security package that helps provide an authentication service to provide secure communications between client and server. For more information, see the MSDN article, Secure Channel.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could access random e-mail message fragments available on the affected server.
How could an attacker exploit the vulnerability?
An attacker could try to exploit the vulnerability by sending a set of specially crafted SMTP commands to an affected SMTP server. The attacker could then read information in memory on the affected system.
What systems are primarily at risk from the vulnerability?
All operating systems that use the native SMTP component, which is provided as part of the operating system, are at risk from this vulnerability.
What does the update do?
The security update addresses the vulnerability by correcting the manner in which the SMTP component allocates memory for interpreting SMTP command responses.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through responsible disclosure.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.
Other Information
Microsoft Active Protections Program (MAPP)
To improve security protections for customers, Microsoft provides vulnerability information to major security software providers in advance of each monthly security update release. Security software providers can then use this vulnerability information to provide updated protections to customers via their security software or devices, such as antivirus, network-based intrusion detection systems, or host-based intrusion prevention systems. To determine whether active protections are available from security software providers, please visit the active protections Web sites provided by program partners, listed in Microsoft Active Protections Program (MAPP) Partners.
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Support
•
Customers in the U.S. and Canada can receive technical support from Security Support or 1-866-PCSAFETY. There is no charge for support calls that are associated with security updates. For more information about available support options, see Microsoft Help and Support.
•
International customers can receive support from their local Microsoft subsidiaries. There is no charge for support that is associated with security updates. For more information about how to contact Microsoft for support issues, visit the International Support Web site.
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 (April 13, 2010): Bulletin published.
•
V1.1 (April 14, 2010): Added an entry to the Update FAQ to clarify the Microsoft Exchange servicing model. Also corrected the Configuration Manager 2007 detection value for Microsoft Exchange Server 2000 Service Pack 3 and the installation switches for Microsoft Exchange Server 2000 Service Pack 3 and Microsoft Exchange Server 2003 Service Pack 2.
•
V1.2 (April 15, 2010): Added an entry in the Update FAQ to announce a detection change to the update for Microsoft Exchange Server 2000 Service Pack 3. This is a detection change only. There were no changes to the security update files in this bulletin. Customers who have already installed the update successfully do not need to reinstall.
Related
