|
|
|
|
| |
Credit:
The information has been provided by Microsoft Product Security.
The original article can be found at: http://www.microsoft.com/technet/security/Bulletin/MS06-064.mspx
|
| |
Affected Software:
* Microsoft Windows XP Service Pack 1 and Microsoft Windows XP Service Pack 2 - Download the update
* Microsoft Windows XP Professional x64 Edition - Download the update
* Microsoft Windows Server 2003 and Microsoft Windows Server 2003 Service Pack 1 - Download the update
* Microsoft Windows Server 2003 for Itanium-based Systems and Microsoft Windows Server 2003 with SP1 for Itanium-based Systems - Download the update
* Microsoft Windows Server 2003 x64 Edition - Download the update
Non-Affected Software:
* Microsoft Windows 2000 Service Pack 4
ICMP Connection Reset Vulnerability - CVE-2004-0790:
A denial of service vulnerability exists in the IPv6 Windows implementation of the Internet Control Message Protocol (ICMP). An attacker who successfully exploited this vulnerability could cause the affected system to drop an existing TCP connection.
Mitigating Factors for ICMP Connection Reset Vulnerability - CVE-2004-0790:
* Firewall best practices and firewall or router configurations that block all ICMP traffic can help protect networks from attacks that originate outside the enterprise perimeter. Best practices recommend that systems that are connected to the Internet have a minimal number of ports exposed.
* IPv6 support is not installed by default on Windows XP Service Pack 1, Windows XP Service Pack 2, Windows Server 2003 and Windows Server 2003 Service Pack 1.
* An attacker s system must belong to the same IPv6 network as the target system.
* An attacker must first predict or discover the IP address and port information of the source and of the destination of an existing TCP network connection.
* This attack would have to be performed on each TCP connection that was targeted for reset. Many applications will automatically restore connections that have been reset.
Workarounds for ICMP Connection Reset Vulnerability - CVE-2004-0790:
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.
* Uninstall IPv6.
For the IPv6 protocol for Windows XP with SP2, Windows XP with SP1, or Windows Server 2003, do the following:
1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Click Microsoft TCP/IP version 6 (for Windows XP with SP2 or Windows Server 2003) or Microsoft IPv6 Developer Edition (for Windows XP with SP1), and then click Uninstall.
4. When prompted to confirm the removal of the Microsoft IPv6 Developer Edition or Microsoft TCP/IP version 6 protocol, click OK.
Alternately, from the Windows XP or Windows Server 2003 desktop do the following:
1. Click Start, point to Programs, point to Accessories.
2. Click Command Prompt.
3. At the command prompt, type netsh interface ipv6 uninstall.
Impact of Workaround: Uninstalling IPv6 would result in the system not being able to communicate with other hosts on an IPv6 configured network.
* Block all ICMP network packets at the firewall or at the router:
ICMP network packets are used to initiate a connection with the affected components. Blocking them at the firewall or at the router will help protect systems that are behind that firewall or router from attempts to exploit this vulnerability. We recommend that you block all unsolicited inbound communication from the Internet.
Impact of Workaround: This workaround can also negatively impact performance by preventing TCP from optimizing network communication. ICMP network packets can eliminate fragmentation at routers connecting networks with different MTUs. Fragmentation reduces TCP throughput and increases network congestion.
Note: Windows XP Service Pack 1 Firewall is unable to handle IPv6 network traffic. In order to ensure protection for your Windows XP Service Pack 1 system using the Internet Connection Firewall you should apply the update identified in KB Article 817778 Overview of the Advanced Networking Pack for Windows XP .
* Block ICMP traffic by using IPSec on the affected systems.
Use Internet Protocol security (IPSec) to help protect network communications. Detailed information about IPSec and about how to apply filters is available in Microsoft Knowledge Base Article 313190 and Microsoft Knowledge Base Article 813878.
Impact of Workaround: This workaround can also negatively impact performance by preventing TCP from optimizing network communication. ICMP network packets can eliminate fragmentation at routers connecting networks with different MTUs. Fragmentation reduces TCP throughput and increases network congestion.
FAQ for ICMP Connection Reset Vulnerability - CVE-2004-0790:
What is the scope of the vulnerability?
A denial of service vulnerability exists in Windows in the IPv6 implementation of the Internet Control Message Protocol (ICMP). An attacker who successfully exploited this vulnerability could cause the affected system to drop an existing TCP connection.
What causes the vulnerability?
Specially crafted ICMP packets are being parsed when they should be dropped which may cause the reset of an existing connection.
What is IPv6?
Internet Protocol version 6 (IPv6), a new suite of standard protocols for the network layer of the Internet, is built into Microsoft Windows XP and later. IPv6 is designed to solve many of the problems of the current version of IP (known as IPv4) such as address depletion, security, autoconfiguration, and extensibility. To learn more about IPv6, please read the following Microsoft FAQ for IPv6.
What is TCP/IP?
TCP/IP is a set of networking protocols. TCP/IP includes standards for how computers communicate and conventions for connecting networks and for routing traffic. For more information about TCP/IP, see the following Microsoft Web site.
What is ICMP?
Internet Control Message Protocol (ICMP) is a required TCP/IP standard. "Internet Control Message Protocol (ICMP)." Hosts and routers that use IP communication can report errors and exchange limited control and status information using ICMP.
ICMP messages are usually sent automatically in one of the following situations:
* An IP datagram cannot reach its destination.
* An IP router (gateway) cannot forward datagrams at the current rate of transmission.
* An IP router redirects the sending host to a better route to the destination.
You can use the ping command to send ICMP echo request messages and to record the receipt of ICMP echo reply messages. By using these messages, you can detect network or host communication failures and troubleshoot common TCP/IP connectivity problems. For more information about ICMP, see the following Microsoft Web site.
What might an attacker use the vulnerability to do?
An attacker who exploited this vulnerability could cause the affected system to reset TCP connections.
Who could exploit the vulnerability?
Any anonymous user who could deliver a specially crafted message to the affected system could try to exploit this vulnerability. An attacker s system must belong to the same IPv6 network as a target system.
How could an attacker exploit the vulnerability?
An attacker could exploit the vulnerability by creating a specially crafted message and sending the message to an affected system. The message could then cause the affected system to reset TCP network connections.
What systems are primarily at risk from the vulnerability?
All affected operating systems are at risk from this vulnerability. However, servers are at primary risk from this vulnerability because they maintain connections with clients that could be vulnerable to the connection reset.
Could the vulnerability be exploited over the Internet?
Yes. An attacker could try to exploit this vulnerability over the Internet. By default, the Microsoft Internet Connection Firewall (ICF) in Windows XP Service Pack 1 and in Windows Server 2003 allows these kinds of network packets and cannot be used to filter them by default. The firewall component in Windows XP Service Pack 2 and Windows Server 2003 Service Pack 1 called Windows Firewall is able to block this traffic. If you are running IPv6 on a Windows XP Service Pack 1 you should apply update identified in KB Article 817778 Overview of the Advanced Networking Pack for Windows XP to get an updated Internet Connection Firewall which is able to handle IPv6 traffic.
What does the update do?
The update removes the vulnerability by modifying the way that the affected operating systems validate ICMP requests.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. This vulnerability has been publicly disclosed as affecting the IPv4 implementation of TCP/IP. It has been assigned Common Vulnerability and Exposure number CVE-2004-0790. There is a variant of this issue that has been assigned Common Vulnerability and Exposure number CVE-2004-0791. The Microsoft security update for CVE-2004-0790 also addresses CVE-2004-0791.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers and had not seen any examples of proof of concept code published when this security bulletin was originally issued.
How does this vulnerability relate to the vulnerability that is corrected by MS05-019?
MS05-19 addressed the same vulnerability in the more commonly adopted and deployed IPv4 implementation of TCP/IP. This update addresses the vulnerability in the IPv6 implementation.
TCP Connection Reset Vulnerability - CVE-2004-0230:
A denial of service vulnerability exists in the IPv6 Windows implementation of TCP. An attacker who successfully exploited this vulnerability could cause the affected system to drop an existing TCP connection.
Mitigating Factors for TCP Connection Reset Vulnerability - CVE-2004-0230:
* An attacker must be able to predict or discover the IP address and port information of the source and of the destination of an existing TCP network connection. An attacker would also have to predict or to learn certain difficult TCP network packet details. Protocols or programs that maintain long sessions and have predictable TCP/IP information are at an increased risk for this issue.
* IPv6 support is not installed by default on Windows XP Service Pack 1 and Windows XP Service Pack 2, Windows Server 2003 and Windows Server 2003 Service Pack 1.
* An attacker's system must belong to the same IPv6 network as the target system.
* Firewall best practices and standard default firewall configurations can help protect networks from attacks that originate outside the enterprise perimeter. Best practices recommend that systems that are connected to the Internet have a minimal number of ports exposed. Affected systems that allow any TCP connections to the Internet may be vulnerable to this issue.
* This attack would have to be performed on each TCP connection that was targeted for reset. Many applications will automatically restore connections that have been reset.
Workarounds for TCP Connection Reset Vulnerability - CVE-2004-0230:
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.
* Uninstall IPv6.
For the IPv6 protocol for Windows XP with SP2, Windows XP with SP1, or Windows Server 2003, do the following:
1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Click Microsoft TCP/IP version 6 (for Windows XP with SP2 or Windows Server 2003) or Microsoft IPv6 Developer Edition (for Windows XP with SP1), and then click Uninstall.
4. When prompted to confirm the removal of the Microsoft IPv6 Developer Edition or Microsoft TCP/IP version 6 protocol, click OK.
Alternately, from the Windows XP or Windows Server 2003 desktop do the following:
1. Click Start, point to Programs, point to Accessories.
2. Click Command Prompt.
3. At the command prompt, type netsh interface ipv6 uninstall.
Impact of Workaround: Uninstalling IPv6 would result in the system not being able to communicate with other hosts on an IPv6 configured network.
FAQ for TCP Connection Reset Vulnerability - CVE-2004-0230:
What is the scope of the vulnerability?
A denial of service vulnerability exists in the IPv6 Windows implementation of TCP. An attacker who successfully exploited this vulnerability could cause the affected system to drop an existing TCP connection.
What causes the vulnerability?
Specially crafted TCP packets are being parsed when they should be dropped which may cause the reset of an existing connection.
What is IPv6?
Internet Protocol version 6 (IPv6), a new suite of standard protocols for the network layer of the Internet, is built into Microsoft Windows XP and later. IPv6 is designed to solve many of the problems of the current version of IP (known as IPv4) such as address depletion, security, autoconfiguration, and extensibility. To learn more about IPv6, please read the following Microsoft FAQ for IPv6.
What is TCP/IP?
TCP/IP is a set of networking protocols. TCP/IP includes standards for how computers communicate and conventions for connecting networks and for routing traffic. For more information about TCP/IP, see the following Microsoft Web site.
What might an attacker use the vulnerability to do?
An attacker who exploited this vulnerability could cause the affected system to reset TCP connections.
Who could exploit the vulnerability?
Any anonymous user who could deliver a specially crafted message to the affected system and learn or predict the required TCP details could try to exploit this vulnerability. An attacker s system must belong to the same IPv6 network as a target system.
How could an attacker exploit the vulnerability?
An attacker could exploit the vulnerability by creating a specially crafted message and sending the message to an affected system. The message could then cause the affected system to reset TCP connections.
An attacker must be able to predict or discover the IP address and port information of the source and of the destination of an existing TCP network connection. An attacker would also have to predict or learn certain difficult TCP network packet details.
What systems are primarily at risk from the vulnerability?
All affected operating systems are at risk from this vulnerability. However, servers are at primary risk from this vulnerability because they maintain connections with clients that could be vulnerable to the connection reset. Protocols or programs that maintain long sessions and have predictable TCP/IP information are at an increased risk to this issue.
Could the vulnerability be exploited over the Internet?
Yes. An attacker could try to exploit this vulnerability over the Internet.
What does the update do?
The update removes the vulnerability by modifying the way that the affected operating systems validate TCP requests.
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-2004-0230.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had seen examples of proof of concept code published publicly but had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.
Does applying this security update help protect customers from the code that has been published publicly that attempts to exploit this vulnerability?
Yes. This security update addresses the proof of concept code that has been publicly published. The vulnerability that has been addressed has been assigned the Common Vulnerability and Exposure number CVE-2004-0230.
How does this vulnerability relate to the vulnerability that is corrected by MS05-019?
MS05-19 addressed the same vulnerability in the more commonly adopted and deployed IPv4 implementation of TCP/IP. This update addresses the vulnerability in the IPv6 implementation.
Spoofed Connection Request Vulnerability - CVE-2005-0688:
A denial of service vulnerability exists in Windows in the IPv6 implementation of TCP/IP. An attacker who successfully exploited this vulnerability could cause the affected system to stop responding.
Mitigating Factors for Spoofed Connection Request Vulnerability - CVE-2005-0688:
* IPv6 support is not installed by default on Windows XP Service Pack 1, Windows XP Service Pack 2 and Windows Server 2003 and Windows Server 2003 Service Pack 1.
* An attacker s system must belong to the same IPv6 network as the target system.
* The affected system return to a normal operational state after the specially crafted packets are finished processing.
* A typical network deployment scenario would limit the attack to an individual network segment as most routers will not forward these kinds of specially crafted TCP/IP network packets.
* Firewall best practices and standard default firewall configurations can help protect networks from attacks that originate outside the enterprise perimeter. Best practices recommend that systems that are connected to the Internet have a minimal number of ports exposed. Affected systems that allow any IP connections to the Internet may be vulnerable to this issue.
Workarounds for Spoofed Connection Request Vulnerability - CVE-2005-0688:
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.
* Uninstall IPv6.
For the IPv6 protocol for Windows XP with SP2, Windows XP with SP1, or Windows Server 2003, do the following:
1. Log on to the computer with a user account that has privileges to change network configuration.
2. Click Start, click Control Panel, and then double-click Network Connections.
3. Click Microsoft TCP/IP version 6 (for Windows XP with SP2 or Windows Server 2003) or Microsoft IPv6 Developer Edition (for Windows XP with SP1), and then click Uninstall.
4. When prompted to confirm the removal of the Microsoft IPv6 Developer Edition or Microsoft TCP/IP version 6 protocol, click OK.
Alternately, from the Windows XP or Windows Server 2003 desktop do the following:
1. Click Start, point to Programs, point to Accessories.
2. Click Command Prompt.
3. At the command prompt, type netsh interface ipv6 uninstall.
Impact of Workaround: Uninstalling IPv6 would result in the system not being able to communicate with other hosts on an IPv6 configured network.
FAQ for Spoofed Connection Request Vulnerability - CVE-2005-0688:
What is the scope of the vulnerability?
This is a denial of service vulnerability. An attacker who exploited this vulnerability could cause the affected system to stop responding for a limited time as a result of excessive CPU utilization. During that time, affected systems cannot respond to requests. Note that the denial of service vulnerability would not allow an attacker to execute code or elevate their user rights, but it could cause the affected system to stop accepting requests.
What causes the vulnerability?
The affected operating systems perform incomplete validation of TCP/IP network packets. This vulnerability occurs when a Transmission Control Protocol (TCP) SYN packet is received with a spoofed source Internet Protocol (IP) address and port number that is identical to that of the destination IP address and port. The effect of this makes it appear that the host computer has sent a packet to itself. If this attack is successful, a loop is created and extra computer CPU time is used.
What is IPv6?
Internet Protocol version 6 (IPv6), a new suite of standard protocols for the network layer of the Internet, is built into Microsoft Windows XP and later. IPv6 is designed to solve many of the problems of the current version of IP (known as IPv4) such as address depletion, security, autoconfiguration, and extensibility. To learn more about IPv6, please read the following FAQ for IPv6.
What is TCP/IP?
TCP/IP is a set of networking protocols. TCP/IP includes standards for how computers communicate and conventions for connecting networks and for routing traffic. For more information about TCP/IP, see the following. For more information about TCP/IP, see the following Microsoft Web site.
What might an attacker use the vulnerability to do?
An attacker who exploited this vulnerability could cause the affected system to stop responding.
Who could exploit the vulnerability?
Any anonymous user who could deliver a specially crafted message to the affected system could try to exploit this vulnerability.
How could an attacker exploit the vulnerability?
An attacker could exploit the vulnerability by creating a specially crafted message and sending the message to an affected system. The message could then cause the affected system to stop responding.
What systems are primarily at risk from the vulnerability?
All affected operating systems are at risk from this vulnerability.
Could the vulnerability be exploited over the Internet?
Yes. An attacker could try to exploit this vulnerability over the Internet. However, this attack requires that routers forward malformed TCP/IP network packets. Most routers will not forward these kinds of malformed TCP/IP network packets.
What does the update do?
The update removes the vulnerability by modifying the way that the affected operating systems validate TCP/IP requests.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
Yes. This vulnerability has been publicly disclosed for the IPv4 implementation of TCP/IP. It has been assigned Common Vulnerability and Exposure number CVE-2005-0688. It also has been named Land Attack by the larger security community.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had seen examples of proof of concept code published publicly but had not received any information to indicate that this vulnerability had been publicly used to attack customers using IPv6 when this security bulletin was originally issued.
Does applying this security update help protect customers from the code that has been published publicly that attempts to exploit this vulnerability?
Yes. This security update addresses the vulnerability that is demonstrated by the existing proof of concept code that has been published.
How does this vulnerability relate to the vulnerability that is corrected by MS05-019?
MS05-19 addressed the same vulnerability in the more commonly adopted and deployed IPv4 implementation of TCP/IP. This update addresses the vulnerability in the IPv6 implementation.
|
|
|
|
|
