Microsoft fixes critical PrintNightmare and Office document vulnerabilities in Windows 10

Surface Laptop 4 Amd 2021 Lid
Surface Laptop 4 Amd 2021 Lid (Image credit: Daniel Rubino / Windows Central)

What you need to know

  • Microsoft addressed 66 security vulnerabilities in its September 2021 Patch Tuesday update.
  • The update addresses the PrintNightmare and Office document vulnerabilities.
  • The PrintNightmare and Office document vulnerabilities were rated as critical.

Microsoft rolled out its Patch Tuesday update for Windows 10 yesterday. The update includes fixes for 66 security vulnerabilities, including one that addresses an Office document vulnerability. That Office vulnerability could be utilized by attackers to trick people into opening malicious files.

We broke down how attackers can use this vulnerability in greater detail last week. To summarize, the vulnerability labeled as Windows CVE-2021-40444 can be exploited by using ActiveX controls in an Office document. If people are tricked into opening files and disabling Protected View, an attacker can get malware onto a computer.

Microsoft's documentation on the security vulnerability now includes an update:

Microsoft has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. Please see the FAQ for important information about which updates are applicable to your system.

The Office document vulnerability could be used in conjunction with other issues, such as the recent bug in Outlook that showed spoofed domains inside genuine contact cards.

Microsoft also released an update for the Windows Print Spooler Remote Code Execution Vulnerability, which is labeled CVE-2021-36958. The Print Spooler vulnerability caused a wide range of problems, including attackers being able to place ransomware onto vulnerable PCs.

Security expert Benjamin Delpy confirmed to BleepingComputer that the bug was fixed.

Microsoft has a full list of all addressed security issues from the September 2021 Patch Tuesday update.

Sean Endicott
News Writer and apps editor

Sean Endicott is a tech journalist at Windows Central, specializing in Windows, Microsoft software, AI, and PCs. He's covered major launches, from Windows 10 and 11 to the rise of AI tools like ChatGPT. Sean's journey began with the Lumia 740, leading to strong ties with app developers. Outside writing, he coaches American football, utilizing Microsoft services to manage his team. He studied broadcast journalism at Nottingham Trent University and is active on X @SeanEndicott_ and Threads @sean_endicott_.