"HTTP 401" error message when you try to access web resources that require Kerberos authentication on a computer that is running Windows 7 or Windows Server 2008 R2

Article translations Article translations
Article ID: 2309371 - View products that this article applies to.
Expand all | Collapse all

On This Page

SYMPTOMS

Consider the following scenario:
  • You have a computer that is running Windows 7 or Windows Server 2008 R2.
  • You configure the FEATURE_USE_CNAME_FOR_SPN_KB911149 registry subkey according to the description in the following Microsoft Knowledge Base article:  
    911149 Error message in Internet Explorer when you try to access a Web site that requires Kerberos authentication on a Windows XP-based computer: "HTTP Error 401 - Unauthorized: Access is denied due to invalid credentials"
  • You try to access a webpage or a web application that requires Kerberos authentication by using the alias (CNAME) resource record. A service principal name (SPN) is configured for the CNAME that is related to the web resource. 
In this scenario, you cannot access these web resources, and you receive an error message that resembles the following: 
HTTP 401
Kerberos authentication failed: gss_accept_sec_context failed: Unspecified GSS failure. Minor code may provide more information, Wrong principal in request

CAUSE

This issue occurs because the SPN for the web resources is only registered with the CNAME.

A Windows 7-based or Windows Server 2008 R2-based client computer requests a Kerberos ticket for the fully qualified domain name (FQDN) of the web resources. This means that the client computer requests the host (A) resource record that corresponds to the CNAME for Kerberos authentication. If the SPN is only registered with the CNAME, access to the web resources fails.

RESOLUTION

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=support
Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

There are no prerequisites to apply this hotfix.

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows 7 and Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
  • The MANIFEST files (.manifest) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MANIFEST files and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x86-based versions of Windows 7
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatformService branch
Dnsapi.dll6.1.7600.20787270,33621-Aug-201006:52x86Not applicable
Dnscacheugc.exe6.1.7600.2078728,67221-Aug-201006:50x86Not applicable
Dnsrslvr.dll6.1.7600.20787132,60821-Aug-201006:52x86Not applicable
Mswsock.dll6.1.7600.20787232,44821-Aug-201006:52x86X86_MICROSOFT-WINDOWS-W..-INFRASTRUCTURE-BSP
For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatformService branch
Dnsapi.dll6.1.7600.20787356,86421-Aug-201007:23x64Not applicable
Dnscacheugc.exe6.1.7600.2078730,20821-Aug-201007:22x64Not applicable
Dnsrslvr.dll6.1.7600.20787182,27221-Aug-201007:23x64Not applicable
Mswsock.dll6.1.7600.20787324,60821-Aug-201007:24x64AMD64_MICROSOFT-WINDOWS-W..-INFRASTRUCTURE-BSP
Dnsapi.dll6.1.7600.20787270,33621-Aug-201006:52x86Not applicable
Dnscacheugc.exe6.1.7600.2078728,67221-Aug-201006:50x86Not applicable
For all supported IA-64-based versions of Windows Server 2008 R2
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatformService branch
Dnsapi.dll6.1.7600.20787686,08021-Aug-201006:25IA-64Not applicable
Dnscacheugc.exe6.1.7600.2078762,46421-Aug-201006:22IA-64Not applicable
Dnsrslvr.dll6.1.7600.16385354,81614-Jul-200901:46IA-64Not applicable
Mswsock.dll6.1.7600.20787751,61621-Aug-201006:27IA-64IA64_MICROSOFT-WINDOWS-W..-INFRASTRUCTURE-BSP
Dnsapi.dll6.1.7600.20787270,33621-Aug-201006:52x86Not applicable
Dnscacheugc.exe6.1.7600.2078728,67221-Aug-201006:50x86Not applicable

WORKAROUND

Workaround for Windows 7 and for Windows Server 2008 R2

To work around this issue, register an SPN for the FQDN of the web resources.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

MORE INFORMATION

For more information about alias (CNAME) resource records, visit the following Microsoft website:
How to add an alias (CNAME) resource record
For more information about the service principal names, visit the following Microsoft website:
Introduction to the service principal names
For more information about how to configure the intranet FQDN of site systems, visit the following Microsoft website:
How to configure the intranet FQDN of site systems
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 file information

Additional file information for Windows 7 and for Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7
Collapse this tableExpand this table
File nameX86_66b104d48bda7aa20d45ffeb40707766_31bf3856ad364e35_6.1.7600.20787_none_095b3b936a80547d.manifest
File versionNot applicable
File size698
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameX86_eb8e796bb038696409a707a4fb1dc5b5_31bf3856ad364e35_6.1.7600.20787_none_ba54d717a5dc0894.manifest
File versionNot applicable
File size719
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameX86_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_e2447611fcc8c2c9.manifest
File versionNot applicable
File size55,896
Date (UTC)21-Aug-2010
Time (UTC)07:21
PlatformNot applicable

File nameX86_microsoft-windows-w..-infrastructure-bsp_31bf3856ad364e35_6.1.7600.20787_none_b8b5503aa7bb1dec.manifest
File versionNot applicable
File size3,128
Date (UTC)21-Aug-2010
Time (UTC)07:21
PlatformNot applicable
Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
Collapse this tableExpand this table
File nameAmd64_0f54e0c0aad401865eed2d240176e95f_31bf3856ad364e35_6.1.7600.20787_none_5d7e253678b52a43.manifest
File versionNot applicable
File size723
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameAmd64_9444dd5b5b5b9a2252c89113f1ee806f_31bf3856ad364e35_6.1.7600.20787_none_40966fe4f2462fe4.manifest
File versionNot applicable
File size702
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameAmd64_b37037d01f71f3cccb11ecdbe9d535ed_31bf3856ad364e35_6.1.7600.20787_none_504fb571c6cb7014.manifest
File versionNot applicable
File size1,046
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameAmd64_b64c23f4a9b5bc0d8f178405218f9384_31bf3856ad364e35_6.1.7600.20787_none_4db31efecdcc5573.manifest
File versionNot applicable
File size1,086
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameAmd64_eb8e796bb038696409a707a4fb1dc5b5_31bf3856ad364e35_6.1.7600.20787_none_1673729b5e3979ca.manifest
File versionNot applicable
File size721
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameAmd64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_3e631195b52633ff.manifest
File versionNot applicable
File size55,902
Date (UTC)21-Aug-2010
Time (UTC)08:28
PlatformNot applicable

File nameAmd64_microsoft-windows-w..-infrastructure-bsp_31bf3856ad364e35_6.1.7600.20787_none_14d3ebbe60188f22.manifest
File versionNot applicable
File size3,132
Date (UTC)21-Aug-2010
Time (UTC)08:28
PlatformNot applicable

File nameWow64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_48b7bbe7e986f5fa.manifest
File versionNot applicable
File size51,900
Date (UTC)21-Aug-2010
Time (UTC)07:15
PlatformNot applicable
Additional files for all supported IA-64-based versions of Windows Server 2008 R2
Collapse this tableExpand this table
File nameIa64_5eaeaf11e60fb8089c8ec49183775abf_31bf3856ad364e35_6.1.7600.20787_none_b17171b0668ff744.manifest
File versionNot applicable
File size721
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameIa64_bade0e6460218b1ced3a8892912174ca_31bf3856ad364e35_6.1.7600.20787_none_929bd68b80088973.manifest
File versionNot applicable
File size1,044
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameIa64_eb8e796bb038696409a707a4fb1dc5b5_31bf3856ad364e35_6.1.7600.20787_none_ba567b0da5da1190.manifest
File versionNot applicable
File size720
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameIa64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_e2461a07fcc6cbc5.manifest
File versionNot applicable
File size57,759
Date (UTC)21-Aug-2010
Time (UTC)12:51
PlatformNot applicable

File nameIa64_microsoft-windows-w..-infrastructure-bsp_31bf3856ad364e35_6.1.7600.20787_none_b8b6f430a7b926e8.manifest
File versionNot applicable
File size3,130
Date (UTC)21-Aug-2010
Time (UTC)08:13
PlatformNot applicable

File nameWow64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_48b7bbe7e986f5fa.manifest
File versionNot applicable
File size51,900
Date (UTC)21-Aug-2010
Time (UTC)07:15
PlatformNot applicable

Properties

Article ID: 2309371 - Last Review: October 13, 2010 - Revision: 1.0
APPLIES TO
  • Windows 7 Enterprise
  • Windows 7 Professional
  • Windows 7 Ultimate
  • Windows Server 2008 R2 Standard
  • Windows Server 2008 R2 Enterprise
  • Windows Server 2008 R2 Datacenter
  • Windows Server 2008 R2 Foundation
  • Windows Web Server 2008 R2
  • Windows Server 2008 R2 for Itanium-Based Systems
Keywords: 
kbautohotfix kbqfe kbhotfixserver kbfix kbsurveynew kbexpertiseinter KB2309371

Give Feedback

 

Contact us for more help

Contact us for more help
Connect with Answer Desk for expert help.
Get more support from smallbusiness.support.microsoft.com