No. CVE-2021-34527
A Microsoft Windows bug is being used in attacks
Yes. Attackers are using this right now.
What to do
Apply the vendor's update. If there is none, stop using it or cut it off from the internet.
- Confirmed in attacks
- Nov 3, 2021
- Product
- Microsoft Windows
- Ransomware
- Used by gangs
- Attack likelihood, next 30 days
- over 99%
Attack likelihood is EPSS, a daily estimate from FIRST.org of how likely this bug is to be used in attacks in the next 30 days.
The official description
Microsoft Windows Print Spooler contains an unspecified vulnerability due to the Windows Print Spooler service improperly performing privileged file operations. Successful exploitation allows an attacker to perform remote code execution with SYSTEM privileges. The vulnerability is also known under the moniker of PrintNightmare.
Required action: Apply updates per vendor instructions.
For your tech helper
A read-only checklist for whoever helps you with your computer, or an AI assistant. Paste it into Claude, ChatGPT or a coding agent; it only looks and changes nothing.
Read-only check, change nothing, send nothing anywhere.
Is Microsoft Windows (CVE-2021-34527) installed or running on this machine or in this project?
1. Find every copy and its version (apps, packages, containers, lockfiles).
2. Compare each version against the vendor's fixed version for CVE-2021-34527. Quote the vendor page you used.
3. Report a table: where, version, fixed version, status (exposed / fixed / not installed / unsure).
4. List the exact update steps, but do not run them.