MS15-122: Description of the security update for Windows Kerberos: November 10, 2015

Applies to: Windows 10Windows Server 2012 R2 DatacenterWindows Server 2012 R2 Standard More

Summary


This security update resolves a security feature bypass in Windows. An attacker could bypass Kerberos authentication on a computer and decrypt drives that have BitLocker enabled. The bypass can be exploited only if the computer has BitLocker enabled without a PIN or USB key, the computer is domain joined, and the attacker has physical access to the computer. 

To learn more about this vulnerability, see Microsoft Security Bulletin MS15-122.

More Information


Important
  • All future security and nonsecurity updates for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 require update 2919355 to be installed. We recommend that you install update 2919355 on your Windows RT 8.1-based, Windows 8.1-based, or Windows Server 2012 R2-based computer so that you receive future updates.
  • If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

Known issues in this security update

Be aware that security update 3081320 in MS15-121 and update 3101746 in MS15-115 were released at the same time as 3101246 in this bulletin, MS15-122.
  • Customers who intend to manually install all three updates on Windows 7 Service Pack 1 or Windows Server 2008 R2 Service Pack 1 should install the updates in the following order: 3101246 first, 3081320 second, and 3101746 third. 
  • Customers who intend to manually install all three updates on Windows 8 or Windows Server 2012 should install the updates in the following order: 3101246 first, 3101746 second, and 3081320 third. 
Note This is handled automatically for customers who have automatic updating enabled. 

How to obtain and install the update


Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to turn on automatic updating, see
Get security updates automatically.

Note For Windows RT and Windows RT 8.1, this update is available through Windows Update only.

More Information