CVE-2021-44228

CVE-2021-44228 is a critical-severity vulnerability in Apache Log4j with a CVSS 3.x base score of 10.0. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-12-10). The underlying weakness is classified as CWE-20.

Key facts

Description

Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.

Frequently asked questions

What is CVE-2021-44228?
Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.
How severe is CVE-2021-44228?
CVE-2021-44228 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-44228 being actively exploited?
Yes. CVE-2021-44228 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-12-10, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-44228?
CVE-2021-44228 primarily affects Apache Log4j. In total, 358 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-44228?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-44228 have an EU (EUVD) identifier?
Yes. CVE-2021-44228 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34768. It is also flagged as exploited in the EUVD (since 2021-12-10).
When was CVE-2021-44228 published?
CVE-2021-44228 was published on 2021-12-10 and last updated on 2026-08-11.

References

Affected products (358)

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