Article ID: 317196
Article Last Modified on 2/13/2007
APPLIES TO
- Microsoft Internet Information Services 5.1
- Microsoft Internet Information Services 5.0
- Microsoft Internet Information Server 4.0
This article was previously published under Q317196
We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 6.0 running on Microsoft Windows Server 2003. IIS 6.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:
SYMPTOMS
A denial of service vulnerability exists in Internet Information Server (IIS) 4.0, Internet Information Services (IIS) 5.0, and IIS 5.1. By exploiting this vulnerability, an attacker can temporarily prevent a Web server from providing Web services.
This vulnerability can only be exploited if the Web server is also configured to provide File Transfer Protocol (FTP) services. IIS 4.0 installs FTP services by default, but IIS 5.0 and 5.1 do not. The IIS Lockdown Tool disables FTP support by default.
This vulnerability does not allow any data on the system to be compromised, nor does it enable the attacker to gain any rights on the system.
CAUSE
This vulnerability results because the FTP implementation in IIS 4.0, 5.0, and 5.1 does not correctly handle a request for the status of the connection if the request has been malformed in a particular way. Receiving such a request results in the failure of the IIS service.
RESOLUTION
Internet Information Services 5.1
The update for this problem is included in the "MS02-018: April 2002 Cumulative Patch for Internet Information Services". For more information about how to obtain this patch, click the following article number to view the article in the Microsoft Knowledge Base:
319733 MS02-018: April 2002 cumulative patch for Internet Information Services
Internet Information Services 5.0
The update for this problem is included in the "MS02-018: April 2002 Cumulative Patch for Internet Information Services". For more information about how to obtain this patch, click the following article number to view the article in the Microsoft Knowledge Base:
319733 MS02-018: April 2002 cumulative patch for Internet Information Services
Internet Information Server 4.0
The update for this problem is included in the "MS02-018: April 2002 Cumulative Patch for Internet Information Services". For more information about how to obtain this patch, click the following article number to view the article in the Microsoft Knowledge Base:
319733 MS02-018: April 2002 cumulative patch for Internet Information Services
STATUS
Internet Information Services 5.1
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Internet Information Services 5.1.
Internet Information Services 5.0
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Internet Information Services 5.0.
Internet Information Server 4.0
Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Internet Information Server 4.0.
MORE INFORMATION
For more information on these vulnerabilities, see the following Microsoft Web site:
For more information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the following article number to view the article in the Microsoft Knowledge Base:
265173 Datacenter Program and Windows 2000 Datacenter Server Product
For more information about how to install multiple hotfixes with only one reboot, click the following article number to view the article in the Microsoft Knowledge Base:
296861 How to install multiple Windows updates or hotfixes with only one reboot
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
Additional query words: kbIIS400500510April2002Rollup security_patch
Keywords: kbbug kbfix kbsecurity kbwin2000presp3fix kbwin2000sp3fix KB317196
