Can things get any worse than this? Microsoft published a security advisory yesterday -- ADV190005 | Guidance to adjust HTTP/2 SETTINGS frames -- which affects Windows Server running Internet Information Services (IIS).
The security issue could be abused to cause CPU usage to increase to 100% until the malicious HTTP/2 "connections are killed by IIS".
The advisory recommends to administrators that they install the February non-security updates for the version of Windows 10 that is installed on an affected device. Microsoft released cumulative updates for all supported versions of Windows 10 on the February Patch Tuesday that included security updates.
The updates that Microsoft refers to in the advisory were released this week for Windows 10 version 1607 to 1803 (the update for Windows 10 version 1809 is being tested in the Release Preview ring currently) and the related Windows Server versions.
No instructions available
It is not the first time that non-security updates update security related content. The main issue with the approach is that it weakens the already-very-weak distinction between the monthly security and non-security releases.
The approach is far from ideal especially for administrators and users who install security-only patches exclusively on devices.
Update: Microsoft published the support article in the meantime.
What makes this particular security advisory even more problematic is that Microsoft asks customers to review a Knowledge Base article that does not exist.
The security advisory was published yesterday, but the essential support article is not published yet (a day after the release). It is possible that Microsoft made an error when it added the link to the page, but someone would certainly have verified the link before hitting the publish button.
It is unclear whether the installation of the updates fixes the issues or if other steps are required to resolve it completely.
This is not the first time that Microsoft released updates or advisories without publishing their support pages. I published Microsoft, please publish support pages before updates in 2016 to raise awareness for the issue.
Users and administrators may encounter Windows updates and patches without option to find out what they actually do, may introduce issues, or have additional steps or requirements.
Administrators could install the patches and hope for the best in this particular case, or wait until Microsoft publishes the support page. Both options are not very pleasant; the first could mean that important steps to protect the server are not implemented because of missing instructions, the second that attacks could hit the server while the administrator waits for Microsoft to release the support page.