KEV Intelligence

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2021-44228

Apache Log4j2

Apache Software Foundation / Apache Log4j2 · affected before log4j-core*

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Severity
CVSS 10.0 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
100.0%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-44228 is an unauthenticated vulnerability affecting Apache Software Foundation 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...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Apache Software Foundation / Apache Log4j2 affected before log4j-core*.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

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 vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.

Vendor Product Affected Status
Apache Software Foundation Apache Log4j2 Before log4j-core* Affected
View vendor advisory (opens in new tab)
Published
10 Dec 2021
Exploitation Reported
10 Dec 2021
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

ransomware apache malware metasploit nuclei_scanner cisa

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 10 Dec 2021

Independent exploitation attestation added to the KEV Intelligence record.

Used in malware

CISA

Recorded 10 Dec 2021

Malware families have been linked to exploitation of this CVE.

Proof of concept available

GitHub

Recorded 09 Dec 2021

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
CISA First 2021-12-10 00:00 UTC
The Shadowserver 2026-06-01 00:00 UTC
Tenable Blog 2026-06-02 14:21 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
0
User-Agents
0

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/vmware_vcenter_log4shell.rb 29 Apr 2025
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-44228.yaml 25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

100.0%

Weaknesses

Improper Input Validation CWE-20 Uncontrolled Resource Consumption CWE-400 Deserialization of Untrusted Data CWE-502

Recent mention · Tenable Blog

Inside the customer environment: Where threat actors, vulnerabilities, and exposed assets intersect

Tenable Research has developed a graph-based model linking 600+ threat groups to real-world customer exposures. It reveals which vulnerabilities sit at the intersection of severity, active exploitation, and organizational risk.Key takeawaysThe "patch everything" strategy is...

Read full advisory

All CVSS Scores

CVSS v3.1 10.0 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS v2.0 9.3 High

AV:N/AC:M/Au:N/C:C/I:C/A:C

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

CERTCC/CVE-2021-44228_scanner

github · Created 2021-12-14 23:33:51 UTC · 346 stars · AI assessment 90%

Scanners for Jar files that may be vulnerable to CVE-2021-44228

logpresso/CVE-2021-44228-Scanner

github · Created 2021-12-11 11:18:46 UTC · 857 stars · AI assessment 90%

Vulnerability scanner and mitigation patch for Log4j2 CVE-2021-44228

Puliczek/CVE-2021-44228-PoC-log4j-bypass-words

github · Created 2021-12-10 22:35:00 UTC · 938 stars · AI assessment 90%

🐱‍💻 ✂️ 🤬 CVE-2021-44228 - LOG4J Java exploit - WAF bypass tricks

jas502n/Log4j2-CVE-2021-44228

github · Created 2021-12-10 05:23:44 UTC · 464 stars · AI assessment 90%

Remote Code Injection In Log4j

tangxiaofeng7/CVE-2021-44228-Apache-Log4j-Rce

github · Created 2021-12-09 15:27:38 UTC · 82 stars · AI assessment 90%

Apache Log4j 远程代码执行

Apache Log4j2 Remote Code Injection

nuclei · Created Unknown

vmware_vcenter_log4shell

metasploit · Created Unknown

Metasploit module for CVE-2021-44228

ubiquiti_unifi_log4shell

metasploit · Created Unknown

Metasploit module for CVE-2021-44228

log4shell_header_injection

metasploit · Created Unknown

Metasploit module for CVE-2021-44228

mobileiron_core_log4shell

metasploit · Created Unknown

Metasploit module for CVE-2021-44228

Timeline

From disclosure to observed exploitation

  1. KEV confirmed by Tenable Blog

    Exploitation attested by an external source

  2. KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  3. Metasploit module available

    Exploit module available

  4. Nuclei template available

    Scanner coverage available

  5. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  6. First public exploitation report

    Exploit observed in malware

  7. CVE published

    Vulnerability disclosed publicly

  8. Public PoC available

    Public proof-of-concept code published

  9. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2021-44228

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2021-44228",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.99999,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

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