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  3. CVE-2023-38831
Exploited in the wildUsed by ransomwareComputers & everyday appsCould reach you

CVE-2023-38831 RARLAB WinRAR: command or code injection

In plain words: The program treats text it receives as instructions instead of plain data. The attacker can run commands on the machine — often the whole device is taken over.

Confirmed exploited by CISA on · US federal patch deadline Sep 14, 2023

What to do

  1. Install RARLAB's security update for WinRAR. 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
RARLAB WinRAR Code Execution Vulnerability
Product
RARLAB WinRAR
CISA description
RARLAB WinRAR contains an unspecified vulnerability that allows an attacker to execute code when a user attempts to view a benign file within a ZIP archive.
Type of flaw
Command or code injection (CWE-351)
Confirmed exploited
Aug 24, 2023 — known to be used in ransomware attacks
US federal patch deadline
Sep 14, 2023

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Answering about CVE-2023-38831 ·

Questions about CVE-2023-38831

Is CVE-2023-38831 being exploited?

Yes. CISA added CVE-2023-38831 to its Known Exploited Vulnerabilities catalog on Aug 24, 2023, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2023-38831?

Install RARLAB's security update for WinRAR. 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-2023-38831?

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

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