CVE REMEDIATION GUIDE
CISA KEV · Known exploitedCriticalFixed-version data available

CVE-2021-44228 remediation guide

Apache Log4j2

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 vuln...

Open CVE record
ProductApache Log4j2
Affected versions2.0-beta9, < 2.7.0, >= 2.0.1 < 2.3.1, >= 2.4.0 < 2.12.2, >= 2.13.0 < 2.15.0, 2.0, < 2019.1, 2019.1, < 10.4.2, 3.0, 4.0, 4.1, 4.2, 5.0, 5.1, < 2021-12-13, 3.1, 8.5, 8.6, 8.7
Fixed versions2.7.0, 2.3.1, 2.12.2, 2.15.0, 2019.1, 10.4.2, 2021-12-13, 3.8.0.12, 8.6.2j-398, 2021-12-16, 3.5, 4.4.1, 2020, 4.70, 2.30, 5.1, 10.0.13, 3.5.4, 2.1.0, 2021.11_1.162
Priority basisImmediate · CVSS 10 · EPSS 100.0%
01

Identify the affected asset

Confirm whether Apache Log4j2 is installed, record the deployed version and installation path, and identify exposed interfaces.

  • Record the product name, package or appliance identifier, and installed version.
  • Identify internet-facing, administrative, API, and internal access paths.
  • Preserve the pre-change configuration and relevant service logs.
02

Validate the affected-version match

Compare the deployed version with the affected range: 2.0-beta9, < 2.7.0, >= 2.0.1 < 2.3.1, >= 2.4.0 < 2.12.2, >= 2.13.0 < 2.15.0, 2.0, < 2019.1, 2019.1, < 10.4.2, 3.0, 4.0, 4.1, 4.2, 5.0, 5.1, < 2021-12-13, 3.1, 8.5, 8.6, 8.7. Treat incomplete inventory results as unresolved.

03

Prioritize with independent signals

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog. Combine this signal with asset criticality, exposure, compensating controls, and business impact.

04

Apply supported remediation

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.

05

Verify the result

Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.

  • Confirm the expected version and package state.
  • Run a functional health check for critical service paths.
  • Review authentication, error, application, and security monitoring logs.
  • Reassess exposure if the supported fix cannot be applied.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.