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Microsoft XML Parser Remote Denial of Service Vulnerability

Risk

Medium

Date Discovered

October 12, 2004

Description

Microsoft XML Parser is prone to a remote denial of service vulnerability when handling malformed requests. The vulnerability can be exploited through the WebDAV XML message handler of Microsoft IIS server. It is reported that this issue requires a remote attacker to create specially crafted WebDAV requests and send them to a vulnerable server over TCP port 80. There is a possibility of increased CPU resource and memory consumption as the IIS server attempts to process these requests. This can eventually lead to a denial of service condition in the server. A reboot is required to restore normal functionality. This vulnerability can also be exposed through other applications that rely on Microsoft XML Parser to process XML messages.

Technologies Affected

  • Avaya DefinityOne Media Servers
  • Avaya DefinityOne Media Servers R10
  • Avaya DefinityOne Media Servers R11
  • Avaya IP600 Media Servers
  • Avaya IP600 Media Servers R10
  • Avaya IP600 Media Servers R11
  • Avaya Modular Messaging (MSS) 1.1.0
  • Avaya Modular Messaging (MSS) 2.0.0
  • Avaya S3400 Message Application Server
  • Avaya S8100 Media Servers
  • Avaya S8100 Media Servers R10
  • Avaya S8100 Media Servers R11
  • Microsoft IIS 5.0
  • Microsoft IIS 5.1
  • Microsoft IIS 6.0
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Advanced Server SP1
  • Microsoft Windows 2000 Advanced Server SP2
  • Microsoft Windows 2000 Advanced Server SP3
  • Microsoft Windows 2000 Advanced Server SP4
  • Microsoft Windows 2000 Datacenter Server
  • Microsoft Windows 2000 Datacenter Server SP1
  • Microsoft Windows 2000 Datacenter Server SP2
  • Microsoft Windows 2000 Datacenter Server SP3
  • Microsoft Windows 2000 Datacenter Server SP4
  • Microsoft Windows 2000 Professional
  • Microsoft Windows 2000 Professional SP1
  • Microsoft Windows 2000 Professional SP2
  • Microsoft Windows 2000 Professional SP3
  • Microsoft Windows 2000 Professional SP4
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Server SP1
  • Microsoft Windows 2000 Server SP2
  • Microsoft Windows 2000 Server SP3
  • Microsoft Windows 2000 Server SP4
  • Microsoft Windows Server 2003 Datacenter Edition
  • Microsoft Windows Server 2003 Datacenter Edition Itanium
  • Microsoft Windows Server 2003 Enterprise Edition
  • Microsoft Windows Server 2003 Enterprise Edition Itanium
  • Microsoft Windows Server 2003 Standard Edition
  • Microsoft Windows Server 2003 Web Edition
  • Microsoft Windows XP 64-bit Edition
  • Microsoft Windows XP 64-bit Edition SP1
  • Microsoft Windows XP 64-bit Edition Version 2003
  • Microsoft Windows XP 64-bit Edition Version 2003 SP1
  • Microsoft Windows XP Home
  • Microsoft Windows XP Home SP1
  • Microsoft Windows XP Home SP2
  • Microsoft Windows XP Professional
  • Microsoft Windows XP Professional SP1
  • Microsoft Windows XP Professional SP2

Recommendations

Block external access at the network boundary, unless external parties require service.

If applicable, ensure that access to the affected Web server is restricted at the network perimeter if the service is not intended to be globally accessible. Do not allow untrusted computers and networks to access the resources. Block access to TCP ports 80 and 443.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.

Network IDS systems may detect and block various attacks against Web services. It is recommended that IDS logs are reviewed on a regular basis to identify potential exploitation attempts. Web server logs should also be audited and reviewed, as they may highlight attack attempts as well.

Disable any services that are not needed.

Review all critical systems and disable any unnecessary services that are not required. This may limit exposure to latent vulnerabilities.
Avaya has released an advisory that acknowledges this vulnerability for Avaya products. Customers are advised to follow Microsoft's guidance for applying patches. Please see the referenced Avaya advisory at the following location for further details: http://support.avaya.com/japple/css/japple?temp.groupID=128450&temp.selectedFamily=128451&temp.selectedProduct=154235&temp.selectedBucket=126655&temp.feedbackState=askForFeedback&temp.documentID=203487&PAGE=avaya.css.CSSLvl1Detail&executeTransaction=avaya.css.UsageUpdate() Microsoft has released a bulletin that includes fixes to address this issue for supported versions of the operating system.

Credits

Discovery is credited to Amit Klein and Sanctum, Inc.
Copyright © Symantec Corporation.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.

Disclaimer
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
Symantec, Symantec products, Symantec Security Response, and secure@symantec.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.

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