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  3. CVE-2019-0543
Exploited in the wildUsed by ransomwareComputers & everyday appsCould reach you

CVE-2019-0543 Microsoft Windows: login or permission bypass

In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.

Confirmed exploited by CISA on · US federal patch deadline Apr 5, 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. Used in ransomware, which spreads to ordinary people and small businesses.

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 Privilege Escalation Vulnerability
Product
Microsoft Windows
CISA description
A privilege escalation vulnerability exists when Windows improperly handles authentication requests. An attacker who successfully exploited this vulnerability could run processes in an elevated context.
Type of flaw
Login or permission bypass (CWE-287)
Confirmed exploited
Mar 15, 2022 — known to be used in ransomware attacks
US federal patch deadline
Apr 5, 2022

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Answering about CVE-2019-0543 ·

Questions about CVE-2019-0543

Is CVE-2019-0543 being exploited?

Yes. CISA added CVE-2019-0543 to its Known Exploited Vulnerabilities catalog on Mar 15, 2022, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2019-0543?

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-2019-0543?

Only if you use Microsoft Windows. Used in ransomware, which spreads to ordinary people and small businesses.

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