Products & Services
Support

Product Categories


Popular Downloads


Manage Software

How to Buy

For Home

Linksys Products Store
Linksys is now part of Belkin
Products for everyone

All Ordering Options

Training & Events Partners
Guest

Vulnerability Alert

Microsoft Windows TCP/IP Connection Exhaustion Denial of Service Vulnerability

 
Threat Type:CWE-399: Resource Management Errors
IntelliShield ID:18959
Version:2
First Published:2009 September 08 18:56 GMT
Last Published:2009 September 11 19:07 GMT
Port: Not available
CVE:CVE-2009-1926
Urgency:Unlikely Use
Credibility:Confirmed
Severity:Mild Damage
CVSS Base:7.8 CVSS Calculator
CVSS Version 2.0
CVSS Temporal:5.8
Related Resources:
View related IPS Signature
 
 
Version Summary:

Microsoft has re-released an alert notification with additional version information regarding the Microsoft Windows TCP/IP connection exhaustion denial of service vulnerability.

 
 
Description

Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

The vulnerability is due to errors in handling malformed TCP/IP packets with small or zero size TCP receive window size.  An unauthenticated, remote attacker could exploit the vulnerability by sending a series of malicious network packets to the vulnerable host.  If successful, the attacker could exhaust available connections, resulting in a DoS condition.

Microsoft has confirmed this vulnerability in a security bulletin and released software updates that correct it.

 
Warning Indicators

Systems running the following versions of Microsoft Windows are vulnerable:

  • Windows 2000 SP4 and prior
    Windows XP SP3 and prior
    Windows XP Professional x64 Edition SP2 and prior
  • Windows Server 2003 SP2 and prior
  • Windows Server 2003 x64 Edition SP2 and prior
  • Windows Vista SP2 and prior
  • Windows Vista x64 Edition SP2 and prior
  • Windows Server 2008 for 32-bit Systems SP2 and prior
  • Windows Server 2008 for x64-based Systems SP2 and prior
  • Windows Server 2008 for Itanium-based Systems SP2 and prior
 
IntelliShield Analysis

To exploit the vulnerability, an attacker must be able to send a series of malicious TCP/IP packets to a vulnerable host.  Systems connected to the Internet are most at risk.  Network filtering devices may flag these packets, because they have very small or zero window sizes, allowing administrators to identify ongoing attacks.

Although Microsoft has confirmed this vulnerability in Windows 2000 and Windows XP, updates for these operating systems will not be released.

An exploit could allow the attacker to exhaust the available TCP/IP connections on a targeted system, preventing the system from establishing additional networks connections.  As a result, authorized users could not gain access to resources on the system.  Sessions already established prior to an attack may persist, allowing some services to remain available.

The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the September 2009 security bulletin release. This Cisco bulletin, which assists administrators in identifying or mitigating these vulnerabilities using Cisco devices, is available at the following link: Cisco Applied Mitigation Bulletin: Microsoft Security Bulletin Release for September 2009

 
Vendor Announcements

Microsoft has re-released a security bulletin at the following link: MS09-048

 
Impact

An unauthenticated, remote attacker could exploit this vulnerability to exhaust available TCP/IP connections, resulting in a DoS condition.

 
Technical Information

This vulnerability is due to errors in handling malformed TCP/IP packets with small or zero size TCP receive window size.  The processing of a malformed packet could cause the Windows TCP stack to continue to wait for network transmissions.  In the event of a malicious packet, no further communication may occur, causing the connection to wait indefinitely in a FIN-WAIT-1 or FIN-WAIT-2 status.  A series of malicious packets could cause the system to keep all available connections in a waiting state, preventing the establishment of other connections.

An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious network packet to a vulnerable system.  When processed, the packet could cause the system to leave a TCP/IP connection in a waiting state.  By sending a series of malicious packets, an attacker could cause the system to exhaust its available connections, resulting in a DoS condition.

 
Safeguards

Administrators are advised to apply the appropriate updates.

Administrators are advised to restrict network access to affected systems.

Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.

Administrators are advised to monitor critical systems.

 
Patches/Software

Microsoft customers can obtain updates directly by using the links in the security bulletin. These updates are also distributed by Windows automatic update features and available on the Windows Update website. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.


Signatures
 
Cisco Intrusion Prevention System (IPS) 6.0
Signature IDSignature NameReleaseLatest Release Date
1330/18TCP Drop - Segment out of windowS6422012 Apr 19 
20644/0Microsoft Windows TCP/IP Orphaned Connections VulnerabilityS4312009 Sep 08 
 
Alert History
 

Version 1, September 8, 2009, 2:56 PM:  Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition.  Updates are available.



Product Sets
 
The security vulnerability applies to the following combinations of products.

Primary Products:
Microsoft, Inc.Windows Server 2003 Datacenter Edition Base, SP1, SP2 | Datacenter Edition, 64-bit (Itanium) Base, SP1, SP2 | Datacenter Edition x64 (AMD/EM64T) Base, SP2 | Enterprise Edition Base, SP1, SP2 | Enterprise Edition, 64-bit (Itanium) Base, SP1, SP2 | Enterprise Edition x64 (AMD/EM64T) Base, SP2 | Standard Edition Base, SP1, SP2 | Standard Edition, 64-bit (Itanium) Base, SP1, SP2 | Standard Edition x64 (AMD/EM64T) Base, SP2 | Web Edition Base, SP1, SP2
Microsoft, Inc.Windows Server 2008 Datacenter Edition Base, SP1, SP2 | Datacenter Edition, 64-bit Base, SP1, SP2 | Itanium-Based Systems Edition Base, SP1, SP2 | Enterprise Edition Base, SP1, SP2 | Enterprise Edition, 64-bit Base, SP1, SP2 | Essential Business Server Standard Base, SP1, SP2 | Essential Business Server Premium Base, SP1, SP2 | Essential Business Server Premium, 64-bit Base, SP1, SP2 | Standard Edition Base, SP1, SP2 | Standard Edition, 64-bit Base, SP1, SP2 | Web Server Base, SP1, SP2 | Web Server, 64-bit Base, SP1, SP2
Microsoft, Inc.Windows Vista Home Basic Base, SP1, SP2 | Home Premium Base, SP1, SP2 | Business Base, SP1, SP2 | Enterprise Base, SP1, SP2 | Ultimate Base, SP1, SP2 | Home Basic x64 Edition Base, SP1, SP2 | Home Premium x64 Edition Base, SP1, SP2 | Business x64 Edition Base, SP1, SP2 | Enterprise x64 Edition Base, SP1, SP2 | Ultimate x64 Edition Base, SP1, SP2

Associated Products:
Microsoft, Inc.Windows 2000 Advanced Server Base, rev.2031, rev.2072, rev.2195, SP1, SP2, SP3, SP4 | Datacenter Server Base, SP1, SP2, SP3, SP4 | Professional Base, SP1, SP2, SP3, SP4 | Server Base, SP1, SP2, SP3, SP4
Microsoft, Inc.Windows XP Home Edition Base, SP1, SP2, SP3 | Professional Edition Base, SP1, SP2, SP3 | Professional x64 (AMD/EM64T) Base, SP1, SP2 | Tablet PC Edition Base, 2005 | Media Center Edition Base, 2005




Alerts and bulletins on the Cisco Security Intelligence Operations Portal are highlighted by analysts in the Cisco Threat Operations Center and represent a subset of the comprehensive content that is available through Cisco Security IntelliShield Alert Manager Service. This customizable threat and vulnerability alert service provides security staff with access to timely, accurate, and credible information about threats and vulnerabilities that may affect their environment.


LEGAL DISCLAIMER
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
Powered by  IntelliShield