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Critical MSRC-CVE-2022-37967 1 CVE

Windows Kerberos Elevation of Privilege Vulnerability

Published Nov 8, 2022 · Updated Oct 10, 2023 · Revision 6

Vendor: Microsoft

Summary

Impact: Elevation of Privilege. Microsoft rating: Critical. Not known to be exploited — Exploitation More Likely. Customer action: Required.

Details

What privileges could be gained by an attacker who successfully exploited the vulnerability?
An attacker who successfully exploited this vulnerability could gain administrator privileges.

How could an attacker exploit this vulnerability?
An authenticated attacker could leverage cryptographic protocol vulnerabilities in Windows Kerberos. If the attacker gains control on the service that is allowed for delegation, they can modify the Kerberos PAC to elevate their privileges.

Where can I find more information about these changes?
For more information please see How to manage the Kerberos and Netlogon Protocol changes related to CVE-2022-37967.

Do I need to take further steps to be protected from this vulnerability?
Yes. Please review the KB article How to manage the Kerberos and Netlogon Protocol changes related to CVE-2022-37967. This recommends that you:
Use audit mode to review logs.
Review third-party servers and clients.
Initially you will not be secure. There are additional actions an administrator needs to take that are outlined in the KB article.
There is a risk of exploitation of the noted vulnerability if you don't take the required actions.
To give administrators time to make corrections that prevent authentication failures, and to provide a choice on when to implement the enforcement, Microsoft is addressing this vulnerability in a phased rollout.
UPDATE: Microsoft has released the October 2023 Windows security updates to implement Phase Five. For more information see KB article.
Please refer to the planned enforcement timeline in the KB article.
When each phase of Windows updates become available, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this CVE. See Microsoft Technical Security Notifications and Security Update Guide Notification System News: Create your profile now – Microsoft Security Response Center.

I am running Windows Server 2022 Datacenter: Azure Edition (Server Core) but the hotpatch (Windows Server 2022 Datacenter: Azure Edition (Hotpatch)) for it is not listed in the Security Updates table. Is there an update that I can apply for this edition of Windows Server 2022?
The update to address this vulnerability for Windows Server 2022 Datacenter: Azure Edition (Server Core) is not hotpatchable and is therefore not included in the November Hotpatch KB (5019080). Customers running Windows Server 2022 Datacenter: Azure Edition (Server Core) as a domain controller should install the update for Windows Server 2022 (5019081). This update will require a computer restart.

Security updates
10.0.17763.4974 — https://support.microsoft.com/help/5031361
10.0.20348.2031 — https://support.microsoft.com/help/5031364
10.0.14393.6351 — https://support.microsoft.com/help/5031362
6.0.6003.22317 — https://support.microsoft.com/help/5031416
6.0.6003.22317 — https://support.microsoft.com/help/5031411
6.1.7601.26769 — https://support.microsoft.com/help/5031408
6.1.7601.26769 — https://support.microsoft.com/help/5031441
6.2.9200.24523 — https://support.microsoft.com/help/5031442
6.2.9200.24523 — https://support.microsoft.com/help/5031427
6.3.9600.21620 — https://support.microsoft.com/help/5031419
6.3.9600.21620 — https://support.microsoft.com/help/5031407

Vulnerabilities 1

Revision history

  1. #6

    Microsoft is announcing the release of the fifth phase of Windows security updates to address this vulnerability. These updates remove support for the registry subkey **KrbtgtFullPacSignature** and remove support for Audit mode. Further, all service tickets without the new PAC signatures will now be denied authentication. Microsoft strongly recommends that customers install the October 2023 updates to be fully protected from this vulnerability, and review [How to manage the Kerberos and Netlogon Protocol changes related to CVE-2022-37967](https://support.microsoft.com/help/5020805) for further information. Customers whose Windows devices are configured to receive automatic updates do not need to take any further action, but should review the article to fully understand the impact of these updates.

  2. #5

    Removed the Security Hotpatch Update for the July 2023 revision as that package doesn't exist for this release cycle. You must install the Security Update to get the updated software.

  3. #4

    Microsoft is announcing the release of the fourth phase of Windows security updates to address this vulnerability. These updates remove the ability to set value 1 for the KrbtgtFullPacSignature subkey, and enable the Enforcement mode (Default) (KrbtgtFullPacSignature = 3) which can be overridden by an Administrator with an explicit Audit setting. Microsoft strongly recommends that customers install the July updates to be fully protected from this vulnerability, and review [How to manage the Kerberos and Netlogon Protocol changes related to CVE-2022-37967](https://support.microsoft.com/help/5020805) for further information. Customers whose Windows devices are configured to receive automatic updates do not need to take any further action.

  4. #3

    Microsoft is announcing the release of the third phase of Windows security updates to address this vulnerability. These updates remove the ability to disable PAC signature addition by setting the KrbtgtFullPacSignature subkey to a value of 0. Microsoft strongly recommends that customers install the June updates to be fully protected from this vulnerability, and review [How to manage the Kerberos and Netlogon Protocol changes related to CVE-2022-37967](https://support.microsoft.com/help/5020805) for further information. Customers whose Windows devices are configured to receive automatic updates do not need to take any further action.

  5. #2

    Microsoft is announcing the release of the second phase of Windows security updates to address this vulnerability. These updates make changes to the Kerberos protocol to audit Windows devices by moving Windows domain controllers to Audit mode. With this update, all devices will be in Audit mode by default. Microsoft strongly recommends that customers install the December updates to be fully protected from this vulnerability. Customers whose Windows devices are configured to receive automatic updates do not need to take any further action. For more information see [KB5020805: How to manage Kerberos protocol changes related to CVE-2022-37967](https://support.microsoft.com/kb/5020805).

  6. #1

    Information published.

References