Is itCheck something

No. CVE-2021-21017

A Adobe Acrobat and Reader bug is being used in attacks

Being used now

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
Adobe Acrobat and Reader
Attack likelihood, next 30 days
86%

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

Acrobat Acrobat and Reader contain a heap-based buffer overflow vulnerability that could allow an unauthenticated attacker to achieve code execution in the context of the current user.

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 Adobe Acrobat and Reader (CVE-2021-21017) 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-2021-21017. 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.

Sources