CVE-2021-44228

Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints

Critical 10.0
Exploited: added to CISA KEV 10 Dec 2021
Used in ransomware campaigns

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.

Key facts

Published: 10 Dec 2021
Last changed: 21 Oct 2025
Assigned by: apache
KEV added: 10 Dec 2021
KEV fix due: 24 Dec 2021
Used in ransomware: Yes, according to CISA
EPSS: 99.999% likely to be exploited in the next 30 days, higher than 100% of CVEs (scores for 15 Nov 2026)
SSVC (CISA): Exploitation: active; Automatable: yes; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

10.0CVSS 3.1, Criticalfrom CISA (ADP container)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

What to do

For all affected software assets for which updates exist, the only acceptable remediation actions are: 1) Apply updates; OR 2) remove affected assets from agency networks. Temporary mitigations using one of the measures provided at https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures are only acceptable until updates are available.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Vendor	Product	Versions
Apache Software Foundation	Apache Log4j2	2.0-beta9 up to but excluding log4j-core* (affected); at 2.3.1 unaffected, at 2.4 affected, at 2.12.2 unaffected, at 2.13.0 affected, at 2.15.0 unaffected

Timeline

10 Dec 2021 Published
10 Dec 2021 CVE-2021-44228 added to CISA KEV
10 Dec 2021 Added to the CISA KEV catalogue