MS01-044: Patch Available for WebDAV Denial of Service (298340)


The information in this article applies to:

  • Microsoft Internet Information Services 5.0
This article was previously published under Q298340

SYMPTOMS

In Internet Information Services (IIS) 5.0, a denial of service vulnerability exists that an attacker could exploit to temporarily disrupt Web services on an IIS 5.0 server.

Mitigating Factors:
  • The effect of an attack would be temporary. The server would automatically resume normal service as soon as the malformed requests stopped arriving.
  • This vulnerability does not provide an attacker with any capability to carry out WebDAV requests.
  • This vulnerability does not provide any capability to compromise data on the server or gain administrative control over it.
  • This vulnerability only affects IIS 5.0.

CAUSE

This vulnerability occurs because of the way that WebDAV handles a particular type of very long, invalid request. The net effect is to cause an access violation that results in the failure of the IIS 5.0 process.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later:
   Date         Time  Version        Size     File name
   ------------------------------------------------------
   12-May-2001  1815  5.0.2195.3608  246,032  Httpext.dll

STATUS

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Internet Information Services 5.0. This problem was first corrected in Windows 2000 Service Pack 3.

MORE INFORMATION

This patch also contains fixes for the problems described in the following Microsoft Knowledge Base article:

297860 IIS 5.0 Security and Post-Windows NT 4.0 SP5 IIS 4.0 Patch Rollup

For more information on this vulnerability, see the following Microsoft Web site:

http://www.microsoft.com/technet/security/bulletin/ms01-044.mspx

For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 The Datacenter Program and Windows 2000 Datacenter Server Product

For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot

Modification Type:MinorLast Reviewed:10/10/2006
Keywords:kbbug kbfix KbSECBulletin KbSECHack kbSecurity KbSECVulnerability kbWin2000PreSP3Fix kbWin2000sp3fix KB298340
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