Security News > 2020 > November > Microsoft fixes Windows Kerberos authentication issues in OOB update

Microsoft has released out-of-band optional updates to fix a known issue that causes Kerberos authentication problems on enterprise domain controllers after installing security updates released earlier this month to address CVE-2020-17049.
This OOB update comes after Microsoft started investigating the Kerberos authentication issue over the weekend, on November 14.
The update is not available through Windows Update or Microsoft Update channels.
To install it you will have to download the update packages from the Microsoft Update Catalog or use Windows Server Update Services.
Update: Microsoft has released additional out-of-band updates to address the Kerberos auth issues on all impacted Windows versions.
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Related Vulnerability
DATE | CVE | VULNERABILITY TITLE | RISK |
---|---|---|---|
2020-11-11 | CVE-2020-17049 | Incorrect Authorization vulnerability in multiple products A security feature bypass vulnerability exists in the way Key Distribution Center (KDC) determines if a service ticket can be used for delegation via Kerberos Constrained Delegation (KCD). To exploit the vulnerability, a compromised service that is configured to use KCD could tamper with a service ticket that is not valid for delegation to force the KDC to accept it. The update addresses this vulnerability by changing how the KDC validates service tickets used with KCD. | 0.0 |