"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

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=supportNote 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

File name

File version

File size

Date

Time

Platform

Service branch

Dnsapi.dll

6.1.7600.20787

270,336

21-Aug-2010

06:52

x86

Not applicable

Dnscacheugc.exe

6.1.7600.20787

28,672

21-Aug-2010

06:50

x86

Not applicable

Dnsrslvr.dll

6.1.7600.20787

132,608

21-Aug-2010

06:52

x86

Not applicable

Mswsock.dll

6.1.7600.20787

232,448

21-Aug-2010

06:52

x86

X86_MICROSOFT-WINDOWS-W..-INFRASTRUCTURE-BSP

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Service branch

Dnsapi.dll

6.1.7600.20787

356,864

21-Aug-2010

07:23

x64

Not applicable

Dnscacheugc.exe

6.1.7600.20787

30,208

21-Aug-2010

07:22

x64

Not applicable

Dnsrslvr.dll

6.1.7600.20787

182,272

21-Aug-2010

07:23

x64

Not applicable

Mswsock.dll

6.1.7600.20787

324,608

21-Aug-2010

07:24

x64

AMD64_MICROSOFT-WINDOWS-W..-INFRASTRUCTURE-BSP

Dnsapi.dll

6.1.7600.20787

270,336

21-Aug-2010

06:52

x86

Not applicable

Dnscacheugc.exe

6.1.7600.20787

28,672

21-Aug-2010

06:50

x86

Not applicable

For all supported IA-64-based versions of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Service branch

Dnsapi.dll

6.1.7600.20787

686,080

21-Aug-2010

06:25

IA-64

Not applicable

Dnscacheugc.exe

6.1.7600.20787

62,464

21-Aug-2010

06:22

IA-64

Not applicable

Dnsrslvr.dll

6.1.7600.16385

354,816

14-Jul-2009

01:46

IA-64

Not applicable

Mswsock.dll

6.1.7600.20787

751,616

21-Aug-2010

06:27

IA-64

IA64_MICROSOFT-WINDOWS-W..-INFRASTRUCTURE-BSP

Dnsapi.dll

6.1.7600.20787

270,336

21-Aug-2010

06:52

x86

Not applicable

Dnscacheugc.exe

6.1.7600.20787

28,672

21-Aug-2010

06:50

x86

Not 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 recordFor more information about the service principal names, visit the following Microsoft website:

Introduction to the service principal namesFor 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 systemsFor 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

File name

X86_66b104d48bda7aa20d45ffeb40707766_31bf3856ad364e35_6.1.7600.20787_none_095b3b936a80547d.manifest

File version

Not applicable

File size

698

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

X86_eb8e796bb038696409a707a4fb1dc5b5_31bf3856ad364e35_6.1.7600.20787_none_ba54d717a5dc0894.manifest

File version

Not applicable

File size

719

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

X86_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_e2447611fcc8c2c9.manifest

File version

Not applicable

File size

55,896

Date (UTC)

21-Aug-2010

Time (UTC)

07:21

Platform

Not applicable


File name

X86_microsoft-windows-w..-infrastructure-bsp_31bf3856ad364e35_6.1.7600.20787_none_b8b5503aa7bb1dec.manifest

File version

Not applicable

File size

3,128

Date (UTC)

21-Aug-2010

Time (UTC)

07:21

Platform

Not applicable

Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

Amd64_0f54e0c0aad401865eed2d240176e95f_31bf3856ad364e35_6.1.7600.20787_none_5d7e253678b52a43.manifest

File version

Not applicable

File size

723

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Amd64_9444dd5b5b5b9a2252c89113f1ee806f_31bf3856ad364e35_6.1.7600.20787_none_40966fe4f2462fe4.manifest

File version

Not applicable

File size

702

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Amd64_b37037d01f71f3cccb11ecdbe9d535ed_31bf3856ad364e35_6.1.7600.20787_none_504fb571c6cb7014.manifest

File version

Not applicable

File size

1,046

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Amd64_b64c23f4a9b5bc0d8f178405218f9384_31bf3856ad364e35_6.1.7600.20787_none_4db31efecdcc5573.manifest

File version

Not applicable

File size

1,086

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Amd64_eb8e796bb038696409a707a4fb1dc5b5_31bf3856ad364e35_6.1.7600.20787_none_1673729b5e3979ca.manifest

File version

Not applicable

File size

721

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Amd64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_3e631195b52633ff.manifest

File version

Not applicable

File size

55,902

Date (UTC)

21-Aug-2010

Time (UTC)

08:28

Platform

Not applicable


File name

Amd64_microsoft-windows-w..-infrastructure-bsp_31bf3856ad364e35_6.1.7600.20787_none_14d3ebbe60188f22.manifest

File version

Not applicable

File size

3,132

Date (UTC)

21-Aug-2010

Time (UTC)

08:28

Platform

Not applicable


File name

Wow64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_48b7bbe7e986f5fa.manifest

File version

Not applicable

File size

51,900

Date (UTC)

21-Aug-2010

Time (UTC)

07:15

Platform

Not applicable

Additional files for all supported IA-64-based versions of Windows Server 2008 R2

File name

Ia64_5eaeaf11e60fb8089c8ec49183775abf_31bf3856ad364e35_6.1.7600.20787_none_b17171b0668ff744.manifest

File version

Not applicable

File size

721

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Ia64_bade0e6460218b1ced3a8892912174ca_31bf3856ad364e35_6.1.7600.20787_none_929bd68b80088973.manifest

File version

Not applicable

File size

1,044

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Ia64_eb8e796bb038696409a707a4fb1dc5b5_31bf3856ad364e35_6.1.7600.20787_none_ba567b0da5da1190.manifest

File version

Not applicable

File size

720

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Ia64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_e2461a07fcc6cbc5.manifest

File version

Not applicable

File size

57,759

Date (UTC)

21-Aug-2010

Time (UTC)

12:51

Platform

Not applicable


File name

Ia64_microsoft-windows-w..-infrastructure-bsp_31bf3856ad364e35_6.1.7600.20787_none_b8b6f430a7b926e8.manifest

File version

Not applicable

File size

3,130

Date (UTC)

21-Aug-2010

Time (UTC)

08:13

Platform

Not applicable


File name

Wow64_microsoft-windows-dns-client_31bf3856ad364e35_6.1.7600.20787_none_48b7bbe7e986f5fa.manifest

File version

Not applicable

File size

51,900

Date (UTC)

21-Aug-2010

Time (UTC)

07:15

Platform

Not applicable

Need more help?

Expand your skills
Explore Training
Get new features first
Join Microsoft Insiders

Was this information helpful?

Thank you for your feedback!

Thank you for your feedback! It sounds like it might be helpful to connect you to one of our Office support agents.

×