CVE-2021-44228 Apache Log4j2: unsafe data loading
In plain words: The program unpacks saved data from outside without checking it is safe. Usually lets an attacker run code on the server.
Confirmed exploited by CISA on · US federal patch deadline Dec 24, 2021
What to do
- Install Apache's security update for Log4j2. 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.
- Patch anything in this catalog first, ahead of normal patch cycles.
- 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
- Apache Log4j2 Remote Code Execution Vulnerability
- Product
- Apache Log4j2
- CISA description
- Apache Log4j2 contains a vulnerability where JNDI features do not protect against attacker-controlled JNDI-related endpoints, allowing for remote code execution.
- Type of flaw
- Unsafe data loading (CWE-20, CWE-400, CWE-502)
- Confirmed exploited
- Dec 10, 2021 — known to be used in ransomware attacks
- US federal patch deadline
- Dec 24, 2021
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Answering about CVE-2021-44228 ·
Questions about CVE-2021-44228
Is CVE-2021-44228 being exploited?
Yes. CISA added CVE-2021-44228 to its Known Exploited Vulnerabilities catalog on Dec 10, 2021, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2021-44228?
Install Apache's security update for Log4j2. 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-2021-44228?
Only if you use Apache Log4j2. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.