Symptoms
Consider the following scenario:
-
You have Internet Information Services (IIS) 7.0 or 7.5 installed on a computer that is running Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2.
-
You configure authentication settings for a Web site in IIS to only use Basic authentication.
-
You apply an account lockout policy for Active Directory on this computer. Specifically, you specify nonzero value for the Account lockout threshold setting.
-
You try to log on to the Web site by using invalid credentials.
In this scenario, you receive the following error message sooner than expected:
HTTP Error 401.1 - Unauthorized
You do not have permission to view this directory or page using the credentials that you supplied.For example, you specify a value of "3" for the
Account lockout threshold setting. Then, you try to log on to the Web site two times by using invalid credentials. Then, you receive the following error message instead of receiving a third opportunity to supply correct credentials:HTTP Error 401.1 - Unauthorized
You do not have permission to view this directory or page using the credentials that you supplied.Cause
The issue occurs because the authentication module that supports Basic authentication tries to log on two times for each unsuccessful logon. The basic authentication module first treats the logon credentials as having the Unicode encoding. When Windows rejects those credentials, the basic authentication module tries again by treating the credentials as having ASCII encoding. This causes two logon failures for each unsuccessful logon.
Resolution
After you apply this hotfix, the basic authentication module compares the provided credentials in UTF-8 format and the format of the local code page. If there is no difference, the basic authentication module does not try to log on a second time for an unsuccessful logon.
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
You must have IIS 7.0 installed to apply this hotfix. You must apply this hotfix on a computer that is running Windows Vista Service Pack 2 or Windows Server 2008 Service Pack 2. This fix is already included in Windows Server 2008 R2 Service Pack 1.
Restart requirement
You do not have to restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace any other hotfixes.
File information
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 item in Control Panel.
For all supported x86-based versions of Windows Vista and of Windows Server 2008
File name |
File version |
File size |
Date |
Time |
Platform |
---|---|---|---|---|---|
Authbas.dll |
7.0.6002.22352 |
33,792 |
02-Mar-2010 |
16:24 |
x86 |
For all supported x64-based versions of Windows Vista and of Windows Server 2008
File name |
File version |
File size |
Date |
Time |
Platform |
---|---|---|---|---|---|
Authbas.dll |
7.0.6002.22352 |
39,424 |
02-Mar-2010 |
16:19 |
x64 |
For all supported IA-64-based versions of Windows Server 2008
File name |
File version |
File size |
Date |
Time |
Platform |
---|---|---|---|---|---|
Authbas.dll |
7.0.6002.22352 |
81,920 |
02-Mar-2010 |
16:09 |
IA-64 |
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
More Information
Steps to reproduce the problem
On a computer that is running IIS 7.0 or 7.5, you can follow these steps to reproduce the problem:
-
Create a Web site in IIS Manager and only enable Basic authentication for this Web site.
-
Enable the Account Logon Failure auditing policy on the computer.
-
Log on to the Web site by using invalid credentials.
-
Open the Security logs by using Event Viewer. You can find two entries that have the following error message:
An account failed to log on
For more information about how to configure account lockout policies, visit the following Microsoft Web site:
AD DS: Fine-grained password policiesFor more information about how to configure basic authentication, visit the following Microsoft Web site:
Additional file information
Additional File information Windows Server 2008 and Windows Vista
Additional file information for all supported x86-based versions of Windows Server 2008 and Windows Vista
File name |
Update.mum |
File version |
|
File size |
2,540 |
Date (UTC) |
03-Mar-2010 |
Time (UTC) |
01:58 |
File name |
X86_d468d9a71cd2146ec54dcae3085c6a5b_31bf3856ad364e35_6.0.6002.22352_none_1f53e6a6bb6cd996.manifest |
File version |
|
File size |
719 |
Date (UTC) |
03-Mar-2010 |
Time (UTC) |
01:58 |
File name |
X86_microsoft-windows-i..henticationbinaries_31bf3856ad364e35_6.0.6002.22352_none_a20633fa31e23563.manifest |
File version |
|
File size |
4,960 |
Date (UTC) |
02-Mar-2010 |
Time (UTC) |
18:11 |
Additional file information for all supported x64-based versions of Windows Server 2008 and Windows Vista
File name |
Amd64_8ddaf1684e365943a9fc3c89dc188acb_31bf3856ad364e35_6.0.6002.22352_none_2cb3444cc3438b76.manifest |
File version |
|
File size |
1,088 |
Date (UTC) |
03-Mar-2010 |
Time (UTC) |
01:58 |
File name |
Amd64_microsoft-windows-i..henticationbinaries_31bf3856ad364e35_6.0.6002.22352_none_fe24cf7dea3fa699.manifest |
File version |
|
File size |
4,974 |
Date (UTC) |
02-Mar-2010 |
Time (UTC) |
18:04 |
File name |
Update.mum |
File version |
|
File size |
2,558 |
Date (UTC) |
03-Mar-2010 |
Time (UTC) |
01:58 |
File name |
Wow64_microsoft-windows-i..henticationbinaries_31bf3856ad364e35_6.0.6002.22352_none_087979d01ea06894.manifest |
File version |
|
File size |
3,655 |
Date (UTC) |
02-Mar-2010 |
Time (UTC) |
18:02 |
Additional file information for all supported IA-64-based versions of Windows Server 2008 and Windows Vista
File name |
Ia64_33e0486a74d8c786d71fd00ff3bd5bb3_31bf3856ad364e35_6.0.6002.22352_none_c6ce476140526599.manifest |
File version |
|
File size |
1,086 |
Date (UTC) |
03-Mar-2010 |
Time (UTC) |
01:58 |
File name |
Ia64_microsoft-windows-i..henticationbinaries_31bf3856ad364e35_6.0.6002.22352_none_a207d7f031e03e5f.manifest |
File version |
|
File size |
4,967 |
Date (UTC) |
02-Mar-2010 |
Time (UTC) |
17:43 |
File name |
Update.mum |
File version |
|
File size |
1,412 |
Date (UTC) |
03-Mar-2010 |
Time (UTC) |
01:58 |
File name |
Wow64_microsoft-windows-i..henticationbinaries_31bf3856ad364e35_6.0.6002.22352_none_087979d01ea06894.manifest |
File version |
|
File size |
3,655 |
Date (UTC) |
02-Mar-2010 |
Time (UTC) |
18:02 |