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  3. CVE-2021-4034
Exploited in the wildUsed by ransomwareServers & business softwareWork IT

CVE-2021-4034 Red Hat Polkit: memory-safety flaw

In plain words: The program mishandles the memory it uses to keep track of data. A specially made input can scramble that memory. Usually lets an attacker crash the program or run their own code with its permissions.

Confirmed exploited by CISA on · US federal patch deadline Jul 18, 2022

What to do

  1. Install Red Hat's security update for Polkit. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Keep a list of every internet-facing server you run so nothing is forgotten.
  3. Patch anything in this catalog first, ahead of normal patch cycles.
  4. Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.

Who is affected

Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.

The details

Official name
Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
Product
Red Hat Polkit
CISA description
The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.
Type of flaw
Memory-safety flaw (CWE-787)
Confirmed exploited
Jun 27, 2022 — known to be used in ransomware attacks
US federal patch deadline
Jul 18, 2022

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Answering about CVE-2021-4034 ·

Questions about CVE-2021-4034

Is CVE-2021-4034 being exploited?

Yes. CISA added CVE-2021-4034 to its Known Exploited Vulnerabilities catalog on Jun 27, 2022, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2021-4034?

Install Red Hat's security update for Polkit. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.

Am I affected by CVE-2021-4034?

Only if you use Red Hat Polkit. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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