Apache · Log4j2
CVE-2021-44228
Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints
What it is
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.
CISA: Apache Log4j2 contains a vulnerability where JNDI features do not protect against attacker-controlled JNDI-related endpoints, allowing for remote code execution.
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.
Deadline for US federal agencies: December 24, 2021
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-s…
- debian.org/security/2021/dsa-5020
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedora…
- msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44…
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-s…
- Added to the CISA list
- December 10, 2021
- Published
- December 10, 2021
- Severity
- Critical 10.0 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- >99.9% in the top 0.1% of all known vulnerabilities
- Weakness
- CWE-20 CWE-400 CWE-502
- More details
- NVD · CVE.org · CISA
All references (20)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
- https://www.debian.org/security/2021/dsa-5020
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VU57UJDCFIAS…
- https://msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44228-apache-log4j2/
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
- 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
- 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://lists.debian.org/debian-lts-announce/2021/12/msg00007.html
- 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
More exploited flaws from Apache
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| May 1, 2023 | Deserialization of Untrusted Data | Log4j2 | Critical 9.0 | >99.9% |
| Oct 8, 2026 | Command Injection | Struts | High 8.1 | 97% |
| Aug 4, 2026 | Missing Encryption of Sensitive Data | Tomcat | High 7.5 | 99% |
| Apr 16, 2026 | Improper Input Validation | ActiveMQ | High 8.8 | 98% |
| May 1, 2025 | Improper Escaping of Output | HTTP Server | Critical 9.1 | >99.9% |
| Apr 1, 2025 | Path Equivalence | Tomcat | Critical 10.0 | 99.9% |
| Feb 4, 2025 | Forced Browsing | OFBiz | Critical 9.8 | >99.9% |
| Sep 18, 2024 | Improper Access Control | HugeGraph-Server | Critical 9.8 | 99.2% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.