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CVE-2021-44228

Exploitation: active CVSS 10.0 CRITICAL Ransomware: known use

CVSS base score: 10.0 (Critical) CISA · v3.1

Score assigned by CISA's Vulnrichment program; the vendor's CVE record did not include one. Vulnrichment source record →

Apache Log4j2 Remote Code Execution Vulnerability

Vendor: Apache   Product: Log4j2

Description

Apache Log4j2 contains a vulnerability where JNDI features do not protect against attacker-controlled JNDI-related endpoints, allowing for remote code execution.

Research & News Coverage

No mentions found in monitored research blogs or news feeds.

Referenced in Advisories

DateAdvisoryIssuer
2026-08-26 Joint CSA: China-Linked Hacking Group QTFY Targets Military and Critical Infrastructure with Malicious Distributed Systems NSA
2026-07-30 Open Source Software: Security Principles and Practices CISA
2024-11-12 2023 Top Routinely Exploited Vulnerabilities CISA
2024-09-18 People's Republic of China-Linked Actors Compromise Routers and IoT Devices for Botnet Operations FBI
2024-07-25 North Korea Cyber Group Conducts Global Espionage Campaign to Advance Regime’s Military and Nuclear Programs NSA
2024-07-25 North Korea Cyber Group Conducts Global Espionage Campaign to Advance Regime's Military and Nuclear Programs NSA
2024-07-08 People’s Republic of China (PRC) Ministry of State Security APT40 Tradecraft in Action NSA
2024-07-08 APT40 Advisory: PRC MSS Tradecraft in Action NSA
2024-02-15 Threat Actor Leverages Compromised Account of Former Employee to Access State Government Organization CISA

Lifecycle Timeline

Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 307 points from 2021-12-11, tracked daily from 2026-09-09; earlier points are weekly, which dates a spike to within a week. Peak probability 100.0% on 2026-06-20.

Published Applicability

Red Hat CSAF/VEX 4 affected · 122 fixed · 2254 not affected
OSV.dev (incl. GHSA) 14 affected · 10 fixed · 0 not affected
CVE List v5 (CNA container) 3 affected · 0 fixed · 3 not affected

Check whether a specific version is affected → 1 source disagreement

What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.

Detection & Exploitation

Coverage across public collections only: Nuclei and OpenVAS NVT (scan); Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM); Metasploit, Exploit-DB, public GitHub repositories and NVD exploit references (exploit). Absence here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by PoC-in-GitHub (CC0) and filtered to repositories that are still online, contain code, and are starred or at least two weeks old. They are still not vetted: some are fakes and some are malware. Treat them as evidence that code was published, not as code to run.
NVD exploit references are links NVD's analysts tag as exploits; they confirm an exploit was referenced but carry no date. This product uses data from the NVD but is not endorsed or certified by the NVD.
OpenVAS coverage derives from the Greenbone Community Feed, made available under the Open Database License (ODbL) v1.0; its individual Vulnerability Tests are licensed GNU GPL v2.

First seenToolEvidenceEarliest reference
2021-12-09 GitHub PoC Unvetted — public repository Glease/Healer +365 more
2021-12-14 Exploit-DB Direct — curated exploit code Apache Log4j2 2.14.1 - Information Disclosure +2 more
2021-12-15 Metasploit Direct — curated exploit code Log4Shell HTTP Scanner +4 more

Metasploit is dated by the first commit of the module file, Exploit-DB by its publication date, and GitHub repositories by their creation date. GitHub PoC repositories are filtered (still online, contain code, starred or at least two weeks old) but not vetted: some are fakes and some are malware, so they show that code was published, not that it works or is safe to run. Evidence tiers are explained on the About page.

Distribution Status

Debian · apache-log4j1.2 bookworm trixie forky sid scope: local
Debian · apache-log4j2 bookworm 2.15.0-1 trixie 2.15.0-1 forky 2.15.0-1 sid 2.15.0-1 scope: local

Where the distribution has shipped a fix, and in which version. Green means the release has resolved it, amber that it is still open. Data from the Debian Security Tracker, used under Debian's MIT / GPLv2+ terms. Debian is upstream of several other distributions, so a fix here often precedes theirs.

CISA Assessment (Vulnrichment / SSVC)

active
yes
total
10.0 CRITICAL
—
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CWE-502 — Deserialization of Untrusted Data
2025-02-04

Federal Remediation Window (BOD 26-04)

Yes — added 2021-12-10
yes
total control
If the asset isRemediate withinTable 1 row
Publicly exposed 3 days + forensic triage 1 of 16
Not publicly exposed 3 days + forensic triage 9 of 16

BOD 26-04 replaced the single KEV deadline of BOD 22-01 with four inputs: whether the asset is publicly exposed, KEV status, whether exploitation is automatable, and technical impact. Exposure belongs to each agency's asset, not to the CVE, so both outcomes are shown. Automatable and technical impact come from the CISA assessment above. Days are calendar days; for KEV entries the clock starts on the date it was added. Agencies make the final exposure call asset by asset, and may set shorter timelines.

D3FEND Countermeasures

Defensive techniques inferred by MITRE D3FEND from the underlying weakness (CWE-502) — general hardening and detection guidance for this weakness class, not a vendor patch for this specific CVE.

External References