1. Cleus
  2. Zero-days
  3. CVE-2021-36934
Exploited in the wildComputers & everyday appsCould reach you

CVE-2021-36934 Microsoft Windows: privilege escalation

In plain words: Something running with limited rights can promote itself to full control. Turns a small foothold (like a malicious app) into administrator or system-level access.

Confirmed exploited by CISA on · US federal patch deadline Feb 24, 2022

What to do

  1. Install Microsoft's security update for Windows. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Turn on automatic updates for the operating system and for Office, PDF and archive apps.
  3. Be careful with unexpected attachments — documents, .zip/.rar files and shortcuts are common bait.
  4. Use a normal (non-admin) account day to day and keep built-in protection like Microsoft Defender on.

Who is affected

Could reach you. This one is aimed at devices or apps of the kind people own.

What's at risk: Your files, saved passwords and accounts. Many of these let a program that is already running gain full administrator control.

The details

Official name
Microsoft Windows SAM Local Privilege Escalation Vulnerability
Product
Microsoft Windows
CISA description
If a Volume Shadow Copy (VSS) shadow copy of the system drive is available, users can read the SAM file which would allow any user to escalate privileges to SYSTEM level.
Type of flaw
Privilege escalation (CWE-1220)
Confirmed exploited
Feb 10, 2022
US federal patch deadline
Feb 24, 2022

Ask Cleus about it

Ask about a vulnerability, an update, a weird message, or the news. Plain-word answers, free, no account.

Answering about CVE-2021-36934 ·

Questions about CVE-2021-36934

Is CVE-2021-36934 being exploited?

Yes. CISA added CVE-2021-36934 to its Known Exploited Vulnerabilities catalog on Feb 10, 2022, which means there is reliable evidence of real-world attacks.

How do I fix CVE-2021-36934?

Install Microsoft's security update for Windows. If no update exists, follow the vendor's workaround or stop using the product until one ships. Turn on automatic updates for the operating system and for Office, PDF and archive apps.

Am I affected by CVE-2021-36934?

Only if you use Microsoft Windows. This one is aimed at devices or apps of the kind people own.

Other exploited Microsoft vulnerabilities

Newest in the catalog

Search every known exploited vulnerability →