An application or service that calls the InitializeSecurityContext function together with the ISC_REQ_EXTENDED_ERROR flag may encounter a TLS/SSL negotiation failure on a computer that is running Windows Server 2008 R2 or Windows 7

Consider the following scenario:

• An application or a service calls the InitializeSecurityContext function together with the ISC_REQ_EXTENDED_ERROR flag on a computer that is running Windows Server 2008 R2 or Windows 7.
• The application or service relies on the returned attribute ISC_RET_EXTENDED_ERROR flag.

In this scenario, the application or service may encounter a function failure or an exception.

For example, a Transport Layer Security (TLS) negotiation fails when Microsoft Office Communicator Server 2007 R2 is installed on a computer that is running Windows Server 2008 R2. This problem causes some functions not to work in Office Communicator Server 2007 R2.

This problem occurs because the returned attribute flags that are from the InitializeSecurityContext function do not contain the ISC_RET_EXTENDED_ERROR flag. The application relies on the returned ISC_RET_EXTENDED_ERROR flag. Therefore, a function failure or exception occurs.

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: 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

To apply this hotfix, the computer must be running one of the following operating systems:

• Windows Server 2008 R2
• Windows 7

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfix.

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.

Windows Server 2008 R2 and Windows 7 file information note

The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008 R2 or Windows 7

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

For all supported Itanium-based versions of Windows Server 2008 R2

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

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

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

Additional files for all supported x86-based versions of Windows Server 2008 R2 and for Windows 7

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

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

For more information about the InitializeSecurityContext (Schannel) function, visit the following Microsoft Web site:
For more information about the supportability for Office Communications Server 2007 R2 member server role, click the following article number to view the article in the Microsoft Knowledge Base: