For this week’s Patch Tuesday, the first of the year, Microsoft addressed 97 security issues, six of them rated critical. Though six vulnerabilities have been publicly reported, I do not classify them as zero-days. Microsoft has fixed a lot of security related issues and is aware of several known issues that may have inadvertently caused significant server issues including:
- Hyper-V, which no longer starts with the message, “Virtual machine xxx could not be started because the hypervisor is not running.”
- ReFS (Resilient) file systems that are no longer accessible (which is kind of ironic).
- And Windows domain controller boot loops.
There are a variety of known issues this month, and I’m not sure whether we’ll see more issues reported with the January server patches. You can find more information on the risk of deploying these latest updates with our helpful infographic.
Key testing scenarios
There are no reported high-risk changes to the Windows platform this month. However, there is one reported functional change, and an additional feature added.
- Test local and remote printing and test printing over RDP.
- Test site-to-site VPN, including new and existing connections.
- Test reading or processing ETL files.
- Check starting and stopping Hyper-V on your servers.
- Run Transactional NTFS (TxF) and CLFS test scenarios while including tests for ReFS file I/O transfers.
Each month, Microsoft includes a list of known issues that relate to the operating system and platforms included in this update cycle. I’ve referenced a few key issues that relate to the company’s latest builds, including:
- SharePoint Server: Most users cannot access Web.config files in SharePoint Server. The affected group of users does not include farm administrators, local administrators, or members who are managed by the system. For more information, see Users cannot access Web.config files in SharePoint Server (KB5010126).
- After installing the June 21, 2021 (KB5003690) update, some devices cannot install new ones, such as the July 6, 2021 (KB5004945) or later updates. You will receive the error message, “PSFX_E_MATCHING_BINARY_MISSING.” For more information and a workaround, see Source…