security
305 TopicsPrnproc$ Share on Windows Print Server
Hi all, I was wondering if anyone had some information in regards to the pronproc$ share on Windows print servers? I am running a Windows Server 2019 instance and had the share flag as a potential vulnerability for allowing read & execute on the share. From what I can see the built-in users group has this permission on the share. Is this share something the can be locked down for privileges or will it break the functionality of the server's services?1.8KViews0likes2CommentsBLOG: CVE-2024-38063 - Disabling IPv6 binding = fix - or not?
Dear community, in today's LinkedIn Stream and other social media you might have noticed a recent CVE and the recommendation to disable IPv6 in Windows Server and Windows Client. We are talking about this one: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-38063 Reading the advisory carefully, Microsoft, strictly speaking, does not directly recommend disabling (technically remove binding) of IPv6. Citing: "Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors might be helpful in your situation: Systems are not affected if IPv6 is disabled on the target machine." Maybe I am a bit nitpicking here about old experiences and would greatly appreciate a refreshed Microsoft statement on the disablement (unbinding) of IPv6 and the side-effects in 2024. What we have learned in the past - do no disable IPv6 easily. - yes, you can face issues with IPv6 being on by default and unexpected or misconfiguration. Often caused by DHCPv6, especially in the combination of critical domain controllers, Dual Stack ISPs and SoHo routers messing up your DNS. What's the fuss about IPv6? I am not actively using it in corporate / at home. IPv6 is being used in Windows. More specifically non-routable fe80 addresses and loopback ::1 for internal purposes of Windows or other software. One may complain use cases are - unrightfully - not well and transparent documented. Have a read in the past Here are some references that Copilot brings up. Trust my memory, I've read more like this. https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/ipv6-for-the-windows-administrator-why-you-need-to-care-about/ba-p/256251 https://community.spiceworks.com/t/is-it-a-bad-practice-to-disabe-ipv6/781811/9 https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/configure-ipv6-in-windows My personal conclusion Hold on, we need patches for this CVE, but we should not disable IPv6 easily. Please disable IPv6 temporarily, when you cannot patch this CVE immediately / in time. Take notes which system you have had to disable and consider re-enabling once patches have been tested and applied. If you are using IPv6 knowingly, note the NIC configs. They will be lost when using static settings rather DHCPv6. I am sad to see that NetSec people, undoubtedly experts in their area, jump on the bandwaggon esp. on Social Media to easily disgrace the IPv6 by default enablement of Windows Client and Windows Server, telling you the easier story: "Disable IPv6 and you are good / if you do not need it." Let me counter: You might not know you're "needing it" it in the first place. Whenever you are changing system defaults in Windows, mind that Microsoft and other software vendors may not consider these changes in their testing. And the Crowdstrike Black Friday showed us clearly how outlier system configs and unwell testing goes along. Not very well. IPv6 usage and defaults today One of the most recent example that Microsoft is using IPv6 can be found in the Azure Arc Agent (Connected Machine Agent) changelog: "Better handling when IPv6 local loopback is disabled" source: https://learn.microsoft.com/en-us/azure/azure-arc/servers/agent-release-notes How can I disable IPv6, if required? Many roads led to Rome. Windows + X > Terminal / PowerShell (Admin) #save current NIC config into a simple text file Get-NetAdapterBinding -ComponentID "ms_tcpip6" | where Enabled -eq $true | Out-File $env:temp\original-ipv6-config.txt #disable IPv6 on all adapters Get-NetAdapterBinding -ComponentID "ms_tcpip6" | where Enabled -eq $true | Disable-NetAdapterBinding And how to revert the change? Windows + X > Terminal / PowerShell (Admin) #enable IPv6 on all adapters (mind the text file) Get-NetAdapterBinding -ComponentID "ms_tcpip6" | where Enabled -eq $true | Enable-NetAdapterBinding TL:DR Microsoft is using fe80 addresses and loopback ::1 addresses for internal reasons. IPv6 is preferrably used over IPv4 when it is bound to a network adapter, including said special non- routable addresses. Please disable IPv6 temporarily, when you cannot patch this CVE immediately / in time. Take notes of current config. Please share the word and mind that disabling IPv6 can turn your OS into an outlier system, causing immediate or later issue due lack of testing by Microsoft or other software vendors, assuming the defaults, which is IPv6 being turned on.8.1KViews2likes2CommentsUnable to Uninstall Security Update (KB5094128) on Azure Hosted Windows Server 2022 VM
Hi All, I'm building up a system on Azure of Windows Server 2022 VMs for a PoC. Each Windows Server 2022 VM has been created using a company hardened golden image. After configuring the VM successfully, I am unable to run a software. Through research, the solution to run the software is to uninstall 'Security Update for Microsoft Windows (KB5094128)'. The issue is that I cannot uninstall the update normally. I have looked up various solutions and the following have been unsuccessful: Attempt #1 Powershell (Admin): sfc /scannow wusa /uninstall /kb:5094128 Result: Error 0x800f0905. Attempt #2 Powershell (Admin): Dism /Online /Cleanup-Image /CheckHealth Dism /Online /Cleanup-Image /ScanHealth Dism /Online /Cleanup-Image /RestoreHealth wusa /uninstall /kb:5094128 Result: No corruption detected, error 0x800f0905. Attempt #3 Powershell (Admin): net stop wuauserv net stop cryptSvc net stop bits net stop msiserver ren C:\Windows\SoftwareDistribution SoftwareDistribution.old ren C:\Windows\System32\catroot2 catroot2.old net start wuauserv net start cryptSvc net start bits net start msiserver wusa /uninstall /kb:5094128 Result: All services started and stopped. Error error 0x800f0905. Attempt #4 Windows Update Troubleshooter: Running the windows update troubleshooter gives the following output. The event viewer is suggesting there is a corrupted file error, but as seen above nothing is wanting to remove that file. Does anyone have any other options they could suggest? Or has anyone had success with this issue before? Is it a lost cause as we have to use company hardened golden images? Any suggestions would be appreciated!193Views0likes2CommentsHow to check RDP access to the server
Hello, I have a virtual machine running Windows Server 2019 Datacenter with Active Directory, and all users access it via RDP. No specific access configurations have been set up; I wanted to know if it is possible to check how many times a specific user has connected and from which IP address—is that possible? Also, I wanted to ask if it is possible to determine whether a specific user copied files to their local PC using copy/paste during a session. Thank you234Views0likes2Commentsntoskrnl.exe and build version not getting updated after applying KB5078740 on server 2025
I have installed the latest March patch kb5078740 on server 2025 which was upgraded from server 2022. the patch is showing installed but the ntoskrnl.exe and build version is still showing 10.0.26100.4652. Qualys is detecting it as patch not installed based on file version which should be 10.0.21600.32522. Please let me know how to fix this issue.743Views1like1CommentSecure Boot update still pending on deadline day
After checking the registry keys on 2x VMs which run services for a number of important customers I found they both have: UEFICA2023Error 2147942750 Apparently this means they're pending a reboot. https://blog.mindcore.dk/2026/04/secure-boot-certificate-update-intune/ I can't reboot the VM inside working hours, can they be rebooted after the deadline or do I need to disable Secure Boot on the VMs? I'm concerned I'll have to disable Secure Boot before they're next rebooted for Windows updates.84Views0likes1CommentSave the date: Secure Boot Q&A in July
To help, Microsoft is continuing its Q&A series with several opportunities to connect directly with Microsoft experts. Whether you're managing physical servers, virtualized workloads, or working with your hardware partners on firmware readiness, you can get answers to the questions that matter most to your environment. Learn more and add the events to your calendar: 8:00 AM PDT July 1 - Windows Server Secure Boot AMA 8:00 AM PDT July 8 - Secure Boot Office Hours for virtualized environments 7:00 AM - 7:00 PM PDT July 15 - OEM Secure Boot Office Hours If there's a question that's been holding up your rollout—or one you simply want to validate before moving forward—this is a great opportunity to ask. Feel free to post questions ahead of time or join the conversation live. We look forward to seeing you there.170Views1like0CommentsWindows Server 2025 update with error 0x80073712
Hello Can I have some help? Windows Server 2025 Std, V 24H2, OS build: 26100.32522 The 2026-04 Security Update (KB5082063) (26100.32690) fails with the following error: Installation failed: Windows failed to install the following update with error 0x80073712: 2026-04 Security Update (KB5082063) (26100.32690). Thanks in advance MadUrantia348Views0likes2Comments2026-04 Update Breaks Domain Logins
I have an Active Directory domain that is old (from 2000!) that has been upgraded and moved to newer versions of Windows Server and Active Directory. I have domain controller VMs running Windows Server 2025 Standard Edition. Unfortunately they installed the latest 2026-04 patches which my have changed the Kerberos encryption from RC4 to AES. This has resulted in my not being able to log into any Active Directory domain accounts and the domain controllers themselves. I can only log into workstations using the local account. Suffice to say this a nightmare. Any ideas how to fix it since I can't access the usual tools like Active Directory Users and Computers, Hyper-V won't connect to the VMs, etc. Thanks. SSolved5.6KViews2likes8CommentsPhase 2 of Kerberos RC4 hardening begins with the April 2026 Windows security update
Windows updates released in April 2026 and later begin the second deployment phase of protections designed to address a Kerberos information disclosure vulnerability (CVE‑2026‑20833). This second phase continues the shift away from legacy encryption types such as RC4 by moving toward stronger default ticket behavior. After installing the April 2026 update, domain controllers default to supporting Advanced Encryption Standard (AES‑SHA1) encrypted tickets for accounts that do not have an explicit Kerberos encryption type configuration. If your organization relies on service accounts or applications that depend on RC4-based Kerberos service tickets, now is the time to address those dependencies to avoid authentication issues before the Enforcement phase begins in July 2026. Microsoft recommends continuing to monitor the System event log for Kerberos-related audit events and identify and address misconfigurations or remaining dependencies, then enabling enforcement when warning, blocking, or policy events are no longer logged. See How to manage Kerberos KDC usage of RC4 for service account ticket issuance changes related to CVE-2026-20833 and CVE‑2026‑20833 to learn more about the vulnerability, timelines, recommended preparation steps, and configuration options to ensure compliance before Enforcement mode begins in July 2026.8.6KViews1like1Comment