Microsoft Windows Media Services is a feature of Microsoft Windows 2000 Server and is also available as download for Microsoft Windows NT 4.0 Server. Although Windows Media Services supports multicast streaming, there is no direct communication between the server and the users that the server can log. To help with this problem, Windows 2000 Server includes logging capabilities for multicast transmissions and unicast transmissions. This capability is implemented as an Internet Server API (ISAPI) DLL that is named Nsiislog.dll.
There is a flaw in the way that Nsiislog.dll processes incoming requests. A vulnerability exists that could allow an attacker to send communications to the server that would result in a denial of service of Microsoft Internet Information Services (IIS). The denial of service would only affect IIS, and other services on the server would remain unaffected.
Service pack information
To resolve this problem, obtain the latest service pack for Microsoft Windows 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
How to obtain the latest Windows 2000 service pack
Security patch information
The following files are available for download from the Microsoft Download Center:
Microsoft Windows 2000 (all languages except Japanese NEC)
Windows 2000 (Japanese NEC)
Windows NT 4.0
Release Date: May 28, 2003
For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
This update requires Windows NT 4.0 Server Service Pack 6a. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
How to obtain the latest Windows NT 4.0 service pack
Microsoft Windows Media Services 4.1 is included with Windows 2000 Server Service Pack 2 or Windows 2000 Server Service Pack 3.
This patch supports the following Setup switches:
- /?: Displays the list of installation switches.
- /q: Use quiet mode (no user interaction).
- /q:u: Specifies user-quiet mode, which displays some dialog boxes to the user.
- /q:a: Specifies administrator-quiet mode, which does not display any dialog boxes to the user.
- /t:full path: Specifies the temporary working folder.
- /c: Extracts the files without running Setup when it is used with the /t switch.
- /c:cmd: Overrides the install command that was defined by the author.
- /r:n: Never restarts the computer after installation.
- /r:i: Automatically restarts the computer if it is necessary to complete installation.
- /r:a: Always restarts the computer after installation.
- /r:s: Restarts the computer after installation without prompting the user.
To verify that the patch is installed on your computer, confirm that the following registry key exists:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Services\wm817772
To install the patch without any user intervention, type the following command at a command prompt:
WindowsMedia41-KB817772-x86-ENU /q:a /r:n
For additional information about how to deploy this patch with Microsoft Software Update Services, visit the following Microsoft Web site:
You do not have to restart your computer after you apply this patch.
You cannot remove this patch because the Setup technology does not allow for removal and because there is no system-level rollback feature in Microsoft Windows 2000 and Microsoft Windows NT 4.0.
Patch replacement information
This patch does not replace any other hotfixes.
The Windows 2000 version of this patch is replaced by the 822343 security patch. For more information about this patch, click the following article number to view the article in the Microsoft Knowledge Base:
MS03-022: Flaw in ISAPI extension for Windows Media Services could cause code execution
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone
tab in the Date and Time tool in Control Panel.Windows 2000
Date Time Version Size File Name ------------------------------------------------------- 07-Mar-2003 16:40 22.214.171.12431 16,784 Nsiislog.dll 02-Apr-2003 23:27 6.0.2600.0 144,384 Nsisapi.exe 19-May-2003 18:38 6.0.2600.0 122,880 Nsisapi2.exeWindows NT 4.0
Date Time Version Size File Name ------------------------------------------------------- 01-Apr-2003 19:04 126.96.36.19961 15,760 Nsiislog.dll 20-May-2003 15:37 6.0.2600.0 122,368 Nsisapi2.exe
Microsoft has confirmed that this problem may cause a degree of security vulnerability in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Microsoft Windows 2000 Service Pack 4.