windows kerberos authentication breaks due to security updates

Translation: The krbtgt account has not been reset since AES was introduced into the environment.Resolution: Reset the krbtgt account password after ensuring that AES has not been explicitly disabled on the DC. Things break down if you havent reset passwords in years, or if you have mismatched Kerberos Encryption policies. This knownissue can be mitigated by doing one of the following: Set msds-SupportedEncryptionTypes with bitwise or set it to the current default 0x27 to preserve its current value. The beta and preview chanels don't actually seem to preview anything resembling releases, instead they're A/B testing which is useless to anyone outside of Microsoft. Microsoft fixes Windows Kerberos auth issues in emergency updates, Microsoft fixes ODBC connections broken by November updates, Microsoft shares temporary fix for ODBC database connection issues, Microsoft: November updates break ODBC database connections, Microsoft fixes issue causing 0xc000021a blue screen crashes, Those having Event ID 42, this might help:https://dirteam.com/sander/2022/11/09/knowledgebase-you-experience-errors-with-event-id-42-and-source-kdcsvc-on-domain-controllers/. If you have already patched, you need to keep an eye out for the following Kerberos Key Distribution Center events. If updates are not available, you will need to upgrade to a supported version of Windows or move any application or service to a compliant device. Kerberos has replaced the NTLM protocol as thedefault authentication protocolfor domain-connected devices on all Windows versions above Windows 2000. If you have the issue, it will be apparent almost immediately on the DC. Still, the OOB patch fixed most of these issues, and again it was only a problem if you disabled RC4. Identify areas that either are missing PAC signatures or have PAC Signatures that fail validation through the Event Logs triggered during Audit mode. Next StepsInstall updates, if they are available for your version of Windows and you have the applicable ESU license. Also turning on reduced security on the accounts by enable RC4 encryption should also fix it. LAST UPDATED ON NOVEMBER 15, 2022 QUICK READ 1 min Let's get started! Windows Kerberos authentication breaks after November updates (bleepingcomputer.com) three days ago that the November updates break Kerberos "in situations where you have set the 'This account supports Kerberos AES 256 bit encryption' or 'This account . Microsoft confirmed that Kerberos delegation scenarios where . Later versions of this protocol include encryption. The issue only impacts Windows Servers, Windows 10 devices, and vulnerable applications in enterprise environments according to Microsoft. Note Step 1 of installing updates released on or after November 8, 2022will NOT address the security issues inCVE-2022-37967forWindows devices by default. This update will set AES as the default encryption type for session keys on accounts that are not marked with a default encryption type already. By now you should have noticed a pattern. One symptom is that from Server Manager (on my Windows 8.1 client) I get a "Kerberos authentication error" when trying to connect to the Hyper-V server or Essentials. Microsoft released out-of-band emergency updates yesterday to fix the authentication issues, mentioning that the patches must be installed on all Domain Controllers in affected environments. As we reported last week, updates released November 8 or later that were installed on Windows Server with the Domain Controller duties of managing network and identity security requests disrupted Kerberos authentication capabilities, ranging from failures in domain user sign-ins and Group Managed Service Accounts authentication to remote desktop connections not connecting. Kerberos authentication fails on Kerberos delegation scenarios that rely on a front-end service to retrieve a Kerberos ticket on behalf of a user to access a back-end service. This known issue the following KBs KB5007206, KB5007192, KB5007247, KB5007260, KB5007236, KB5007263. After installing the cumulative updates issued during November's Patch Tuesday, business Windows domain controllers experienced Kerberos sign-in failures and other authentication issues. According to the security advisory, the updates address an issue that causes authentication failures related to Kerberos tickets that have been acquired from Service for User to Self. It is a network service that supplies tickets to clients for use in authenticating to services. This is done by adding the following registry value on all domain controllers. NoteThe following updates are not available from Windows Update and will not install automatically. If the signature is incorrect, raise an event andallowthe authentication. Windows Kerberos authentication breaks due to security updates. Click Select a principal and enter the startup account mssql-startup, then click OK. Note: This will allow the use of RC4 session keys, which are considered vulnerable. Can anyone recommend any sites to sign up for notifications to warn us such as what we have just witnessed with MSFT released November patches potential issues? Kerberos replaced the NTLM protocol to be the default authentication protocol for domain connected devices on all Windows versions above Windows 2000. This will exclude use of RC4 on accounts with msDS-SupportedEncryptionTypes value of NULL or 0 and require AES. Authentication protocols enable authentication of users, computers, and services, making it possible for authorized services and users to access resources in a secure manner. I've held off on updating a few windows 2012r2 servers because of this issue. The registry key was not created ("HKEY_LOCAL_MACHINE\System\currentcontrolset\services\kdc\" KrbtgtFullPacSignature) after installing the update. The script is now available for download from GitHub atGitHub - takondo/11Bchecker. So, we are going role back November update completely till Microsoft fix this properly. "This is caused by an issue in how CVE-2020-17049 was addressed in these updates. Blog reader EP has informed me now about further updates in this comment. Fixed our issues, hopefully it works for you. MONITOR events filed duringAudit mode to secure your environment. Kerberos is a computer network authentication protocol which works based on tickets to allow for nodes communicating over a network to prove their identity to one another in a secure manner. what you shoulddo first to help prepare the environment and prevent Kerberos authentication issues, Decrypting the Selection of Supported Kerberos Encryption Types. NoteIf you find anerror with Event ID 42, please seeKB5021131: How to manage the Kerberos protocol changes related to CVE-2022-37966. If you have already installed updates released on or after November 8, 2022, you can detect devices which do not have a common Kerberos Encryption type by looking in the Event Log for Microsoft-Windows-Kerberos-Key-Distribution-Center Event 27, which identifies disjoint encryption types between Kerberos clients and remote servers or services. ENABLEEnforcement mode to addressCVE-2022-37967in your environment. This will allow use of both RC4 and AES on accounts when msDS-SupportedEncryptionTypes value of NULL or 0. After the entire domain is updated and all outstanding tickets have expired, the audit events should no longer appear. Windows Server 2016: KB5021654 For Configuration Manger instructions, seeImport updates from the Microsoft Update Catalog. If no objects are returned via method 1, or 11B checker doesnt return any results for this specific scenario, it would be easier to modify the default supported encryption type for the domain via a registry value change on all the domain controllers (KDCs) within the domain. If you usesecurity-only updates for these versions of Windows Server, you only need to install these standalone updates for the month of November 2022. With the security updates of November 8, 2022, Microsoft has also initiated a gradual change to the Netlogon and Kerberos protocols. You should keep reading. The November 8, 2022 and later Windows updates address security bypass and elevation of privilege vulnerability with Authentication Negotiation by using weak RC4-HMAC negotiation. If this extension is not present, authentication is allowed if the user account predates the certificate. You might be unable to access shared folders on workstations and file shares on servers. A special type of ticket that can be used to obtain other tickets. Also, it doesn't impact mom-hybrid Azure Active Directory environments and those that don't have on-premises Active Directory servers. STEP 1: UPDATE Deploy the November 8, 2022 or later updates to all applicable Windows domain controllers (DCs). BleepingComputer readers also reported three days ago thatthe November updates breakKerberos"in situations where you have set the 'This account supports Kerberos AES 256 bit encryption' or 'This account supports Kerberos AES 128 bit encryption' Account Options set (i.e., msDS-SupportedEncryptionTypes attribute) on user accounts in AD.". Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. 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Event log: SystemSource: Security-KerberosEvent ID: 4. NoteIf you need to change the default Supported Encryption Type for an Active Directory user or computer, manually add and configure the registry key to set the new Supported Encryption Type. More information on potential issues that could appear after installing security updates to mitigate CVE-2020-17049 can be found here. <p>Hi All, </p> <p>We are experiencing the event id 40960 from half of our Windows 10 workstations - ( These workstations are spread across different sites ) . 3 -Enforcement mode. but that's not a real solution for several reasons, not least of which are privacy and regulatory compliance concerns. ?" First, we need to determine if your environment was configured for Kerberos FAST, Compound Identity, Windows Claims or Resource SID Compression. The initial deployment phase starts with the updates released on November 8, 2022 and continues with later Windows updates until theEnforcement phase. We're having problems with our on-premise DCs after installing the November updates. TheKeyDistributionCenter(KDC)encounteredaticketthatitcouldnotvalidatethe If the signature is missing, raise an event and allow the authentication. As noted in CVE-2020-17049, there are three registry setting values for PerformTicketSignature to control it, but in the current implementation you might encounter different issues with each setting.". Kerberos domain-controlled Windows devices using MIT Kerberos realms impacted by this newly acknowledged issue include both domain controllers and read-only domain controllers as explained by Microsoft. To mitigate the issues, you will need to investigate your domain further to find Windows domain controllers that are not up to date. As I understand it most servers would be impacted; ours are set up fairly out of the box. All of the events above would appear on DCs. You must ensure that msDS-SupportedEncryptionTypes are also configured appropriately for the configuration you have deployed. reg add "HKLM\\SYSTEM\\CurrentControlSet\\Services\\Netlogon\\Parameters" /v RequireSeal /t REG\_DWORD /d 0 /f If you obtained a version previously, please download the new version. Client: Windows 7 SP1, Windows 8.1, Windows 10 Enterprise LTSC 2019, Windows 10 Enterprise LTSC 2016, Windows 10 Enterprise 2015 LTSB, Windows 10 20H2 or later, and Windows 11 21H2 or later. "After installing updates released on November 8, 2022 or later on Windows Servers with the Domain Controller role, you might have issues with Kerberos authentication," Microsoft explained. With the November 2022 security update, some things were changed as to how the Kerberos Key Distribution Center (KDC) Service on the Domain Controller determines what encryption types are supported by the KDC and what encryption types are supported by default for users, computers, Group Managed Service Accounts (gMSA), and trust objects within the domain. Next StepsIf you are already running the most up-to-date software and firmware for your non-Windows devices and have verified that there is a common Encryption type available between your Windows domain controllersand your non-Windows devices, you will need to contact your device manufacturer (OEM) for help or replace the devices with ones that are compliant. HKEY_LOCAL_MACHINE\System\currentcontrolset\services\kdc, 1 New signatures are added, but not verified. Top man, valeu.. aqui bateu certo. Within the German blog post November 2022-Updates fr Windows: nderungen am Netlogon- und Kerberos-Protokoll and within the English version Updates for Windows (Nov. 2022): Changes in Netlogon and Kerberos protocol - causing issues affected administrators are discussing strategies how to mitigate the authentification issues. This XML query below can be used to filter for these: You need to evaluate the passwordLastSet attribute for all user accounts (including service accounts) and make sure it is a date later than when Windows Server 2008 (or later) DCs were introduced into the environment. The next issue needing attention is the problem of mismatched Kerberos Encryption Types and missing AES keys. the missing key has an ID 1 and (b.) Microsoft releases another document, explaining further details related to the authentication problem caused by the security update addressing the privilege escalation vulnerabilities in Windows . Updates will be released in phases: the initial phase for updates released on or after November 8, 2022 and the Enforcement phase for updates released on or after April 11, 2023. Contact the device manufacturer (OEM) or software vendorto determine if their software iscompatible withthe latest protocol change. Continue to monitor for additional event logs filed that indicate either missing PAC signatures or validation failures of existing PAC signatures. If you used any workaround or mitigations for this issue, they are no longer needed, and we recommend you remove them. After installing the Windows updates that are dated on or afterNovember 8, 2022,the following registry key is available for the Kerberos protocol: KrbtgtFullPacSignature Prior to the November 2022 update, the KDC made some assumptions: After November 2022 Update the KDC Makes the following decisions: As explained above, the KDC is no longer proactively adding AES support for Kerberos tickets, and if it is NOT configured on the objects then it will more than likely fail if RC4_HMAC_MD5 has been disabled within the environment. If the signature is either missing or invalid, authentication is denied and audit logs are created. reg add "HKLM\\SYSTEM\\CurrentControlSet\\services\\kdc" /v ApplyDefaultDomainPolicy /t REG\_DWORD /d 0 /f Microsoft's New Patch Tuesday Updates Causes Windows Kerberos Authentication to Break Microsoft's New Patch Tuesday Updates Causes Windows Kerberos Authentication to Break The Error Is Affecting Clients and Server Platforms. 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