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CVE-2021-44228 — Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and…

Key facts

CVE-2021-44228 is a Critical (10.0) vulnerability: Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and…. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-12-10), confirming active exploitation in the wild, and is linked to known ransomware campaigns.

Actively exploited — on the CISA KEV catalog

CVE-2021-44228 is listed on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-12-10), confirming exploitation in the wild. It is linked to known ransomware campaigns. Federal remediation deadline: 2021-12-24. Prioritise patching and deploy the detection and prevention rules below.
CVE CVE-2021-44228
Severity Critical (10.0)
CISA KEV Actively exploited (added 2021-12-10) · ransomware
Detection / prevention —
PoC poc.py
Source 2021/CVE-2021-44228/

Details

English | 한국어

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.

Vulnerability Details

Property Value
CVE ID CVE-2021-44228
CVSS Score 10.0

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2021/CVE-2021-44228/poc.py

Usage

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start

# Clone and navigate to CVE directory
cd CVE-2021-44228

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints

Application URL Status
Vulnerable App http://localhost:8080 Shows vulnerability
Patched App http://localhost:8081 Demonstrates fix

Directory Structure

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References

  • http://packetstormsecurity.com/files/165225/Apache-Log4j2-2.14.1-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165260/VMware-Security-Advisory-2021-0028.html
  • http://packetstormsecurity.com/files/165261/Apache-Log4j2-2.14.1-Information-Disclosure.html
  • http://packetstormsecurity.com/files/165270/Apache-Log4j2-2.14.1-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165281/Log4j2-Log4Shell-Regexes.html
  • http://packetstormsecurity.com/files/165282/Log4j-Payload-Generator.html
  • http://packetstormsecurity.com/files/165306/L4sh-Log4j-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165307/Log4j-Remote-Code-Execution-Word-Bypassing.html
  • http://packetstormsecurity.com/files/165311/log4j-scan-Extensive-Scanner.html
  • http://packetstormsecurity.com/files/165371/VMware-Security-Advisory-2021-0028.4.html
  • http://packetstormsecurity.com/files/165532/Log4Shell-HTTP-Header-Injection.html
  • http://packetstormsecurity.com/files/165642/VMware-vCenter-Server-Unauthenticated-Log4Shell-JNDI-Injection-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165673/UniFi-Network-Application-Unauthenticated-Log4Shell-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/167794/Open-Xchange-App-Suite-7.10.x-Cross-Site-Scripting-Command-Injection.html
  • http://packetstormsecurity.com/files/167917/MobileIron-Log4Shell-Remote-Command-Execution.html
  • http://packetstormsecurity.com/files/171626/AD-Manager-Plus-7122-Remote-Code-Execution.html
  • http://seclists.org/fulldisclosure/2022/Dec/2
  • http://seclists.org/fulldisclosure/2022/Jul/11
  • http://seclists.org/fulldisclosure/2022/Mar/23
  • 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
  • http://www.openwall.com/lists/oss-security/2021/12/13/1
  • http://www.openwall.com/lists/oss-security/2021/12/13/2
  • http://www.openwall.com/lists/oss-security/2021/12/14/4
  • http://www.openwall.com/lists/oss-security/2021/12/15/3
  • https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdf
  • https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf
  • https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf
  • https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdf
  • https://github.com/cisagov/log4j-affected-db
  • https://github.com/cisagov/log4j-affected-db/blob/develop/SOFTWARE-LIST.md
  • https://github.com/nu11secur1ty/CVE-mitre/tree/main/CVE-2021-44228
  • https://lists.debian.org/debian-lts-announce/2021/12/msg00007.html
  • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M5CSVUNV4HWZZXGOKNSK6L7RPM7BOKIB/
  • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VU57UJDCFIASIO35GC55JMKSRXJMCDFM/
  • https://logging.apache.org/log4j/2.x/security.html
  • https://msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44228-apache-log4j2/
  • https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032
  • https://security.netapp.com/advisory/ntap-20211210-0007/
  • https://support.apple.com/kb/HT213189
  • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
  • https://twitter.com/kurtseifried/status/1469345530182455296
  • https://www.bentley.com/en/common-vulnerability-exposure/be-2022-0001
  • https://www.debian.org/security/2021/dsa-5020
  • https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html
  • https://www.kb.cert.org/vuls/id/930724
  • https://www.nu11secur1ty.com/2021/12/cve-2021-44228.html
  • https://www.oracle.com/security-alerts/alert-cve-2021-44228.html
  • https://www.oracle.com/security-alerts/cpuapr2022.html
  • https://www.oracle.com/security-alerts/cpujan2022.html
  • http://packetstormsecurity.com/files/165225/Apache-Log4j2-2.14.1-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165260/VMware-Security-Advisory-2021-0028.html
  • http://packetstormsecurity.com/files/165261/Apache-Log4j2-2.14.1-Information-Disclosure.html
  • http://packetstormsecurity.com/files/165270/Apache-Log4j2-2.14.1-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165281/Log4j2-Log4Shell-Regexes.html
  • http://packetstormsecurity.com/files/165282/Log4j-Payload-Generator.html
  • http://packetstormsecurity.com/files/165306/L4sh-Log4j-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165307/Log4j-Remote-Code-Execution-Word-Bypassing.html
  • http://packetstormsecurity.com/files/165311/log4j-scan-Extensive-Scanner.html
  • http://packetstormsecurity.com/files/165371/VMware-Security-Advisory-2021-0028.4.html
  • http://packetstormsecurity.com/files/165532/Log4Shell-HTTP-Header-Injection.html
  • http://packetstormsecurity.com/files/165642/VMware-vCenter-Server-Unauthenticated-Log4Shell-JNDI-Injection-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/165673/UniFi-Network-Application-Unauthenticated-Log4Shell-Remote-Code-Execution.html
  • http://packetstormsecurity.com/files/167794/Open-Xchange-App-Suite-7.10.x-Cross-Site-Scripting-Command-Injection.html
  • http://packetstormsecurity.com/files/167917/MobileIron-Log4Shell-Remote-Command-Execution.html
  • http://packetstormsecurity.com/files/171626/AD-Manager-Plus-7122-Remote-Code-Execution.html
  • http://seclists.org/fulldisclosure/2022/Dec/2
  • http://seclists.org/fulldisclosure/2022/Jul/11
  • http://seclists.org/fulldisclosure/2022/Mar/23
  • 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
  • http://www.openwall.com/lists/oss-security/2021/12/13/1
  • http://www.openwall.com/lists/oss-security/2021/12/13/2
  • http://www.openwall.com/lists/oss-security/2021/12/14/4
  • http://www.openwall.com/lists/oss-security/2021/12/15/3
  • https://cert-portal.siemens.com/productcert/pdf/ssa-397453.pdf
  • https://cert-portal.siemens.com/productcert/pdf/ssa-479842.pdf
  • https://cert-portal.siemens.com/productcert/pdf/ssa-661247.pdf
  • https://cert-portal.siemens.com/productcert/pdf/ssa-714170.pdf
  • https://github.com/cisagov/log4j-affected-db
  • https://github.com/cisagov/log4j-affected-db/blob/develop/SOFTWARE-LIST.md
  • https://github.com/nu11secur1ty/CVE-mitre/tree/main/CVE-2021-44228
  • https://lists.debian.org/debian-lts-announce/2021/12/msg00007.html
  • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M5CSVUNV4HWZZXGOKNSK6L7RPM7BOKIB/
  • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VU57UJDCFIASIO35GC55JMKSRXJMCDFM/
  • https://logging.apache.org/log4j/2.x/security.html
  • https://msrc-blog.microsoft.com/2021/12/11/microsofts-response-to-cve-2021-44228-apache-log4j2/
  • https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0032
  • https://security.netapp.com/advisory/ntap-20211210-0007/
  • https://support.apple.com/kb/HT213189
  • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-log4j-qRuKNEbd
  • https://twitter.com/kurtseifried/status/1469345530182455296
  • https://www.bentley.com/en/common-vulnerability-exposure/be-2022-0001
  • https://www.debian.org/security/2021/dsa-5020
  • https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00646.html
  • https://www.kb.cert.org/vuls/id/930724
  • https://www.nu11secur1ty.com/2021/12/cve-2021-44228.html
  • https://www.oracle.com/security-alerts/alert-cve-2021-44228.html
  • https://www.oracle.com/security-alerts/cpuapr2022.html
  • https://www.oracle.com/security-alerts/cpujan2022.html
  • https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-44228

Generated by PoC Generator on 2026-06-23T17:59:48.96841289

Frequently asked questions

What is CVE-2021-44228?

CVE-2021-44228 is a Critical (10.0) vulnerability: Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and…. This entry ships a detection-only PoC and a Docker test lab. It is on the CISA Known Exploited Vulnerabilities (KEV) catalog (added 2021-12-10), confirming active exploitation in the wild, and is linked to known ransomware campaigns.

How do I detect CVE-2021-44228?

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2021-44228?

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

Is CVE-2021-44228 actively exploited?

Yes. CVE-2021-44228 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2021-12-10, which means it has been exploited in the wild. CISA also links it to known ransomware campaigns. CISA set a federal remediation deadline of 2021-12-24. Prioritise patching and deploy the detection and prevention rules above.

For authorized security testing and research only. See the full source and NVD record.