CVE-2021-4104

HIGHNVD 7.58.9▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.9 because EPSS predicts 81% probability of exploitation within the next 30 days (top 0.4% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, ghsa, nvd
Elevated
8.9EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 81%
CISA-KEV: Not listedEPSS PROB: 81%CVSS: 7.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

JMSAppender in Log4j 1.2 is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration. The attacker can provide TopicBindingName and TopicConnectionFactoryBindingName configurations causing JMSAppender to perform JNDI requests that result in remote code execution in a similar fashion to CVE-2021-44228. Note this issue only affects Log4j 1.2 when specifically configured to use JMSAppender, which is not the default. Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to Log4j 2 as it addresses numerous other issues from the previous versions.

CVSS v3
7.5
EG Score
8.9(high)
EG Risk
73(Track)
EG Risk 73/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity89% × 45%
Exploitation81% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
81%
EPSS %ILE
100%
KEV
Not listed

Published

December 14, 2021

Last Modified

May 28, 2026

Advisory Details (10)

Auto-updated May 29, 2026
Patch available. Sources: redhat, github_pr.
generic
https://www.cve.org/CVERecord?id=CVE-2021-44228
generic

NetApp Product Security

https://security.netapp.com/advisory/ntap-20211223-0007/
generic

Arduino: Remote Code Execution (GLSA 202312-04) — Gentoo security

https://security.gentoo.org/glsa/202312-04
generic

Minecraft Server: Remote Code Execution (GLSA 202312-02) — Gentoo security

https://security.gentoo.org/glsa/202312-02
generic

Ubiquiti UniFi: remote code execution via bundled log4j (GLSA 202310-16) — Gentoo security

https://security.gentoo.org/glsa/202310-16
generic

IBM Spectrum Protect: Multiple Vulnerabilities (GLSA 202209-02) — Gentoo security

https://security.gentoo.org/glsa/202209-02
generic

Security Advisory

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0033
github_pr Patch Available

Restrict LDAP access via JNDI

Patch available: apache/logging-log4j2 rel/2.21.0 (PR #608 merged 2021-12-05)

https://github.com/apache/logging-log4j2/pull/608#issuecomment-990494126
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2021-4104
generic

oss-security - CVE-2022-23302: Deserialization of untrusted data in JMSSink in Apache Log4j 1.x

http://www.openwall.com/lists/oss-security/2022/01/18/3

Vendor Advisories for CVE-2021-4104(20)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(23)

Vendor / EcosystemFixed in / PatchReleasedSource
redhateap7-xml-security-0:2.2.3-2.redhat_00001.1.el7eap2024-11-25redhat
redhateap7-log4j-jboss-logmanager-0:1.2.2-1.Final_redhat_00002.1.ep7.el72024-08-26redhat
redhatjbossweb-0:7.5.32-2.Final_redhat_1.2.ep6.el62022-06-30redhat
redhatpatch2022-06-30redhat
redhatjbossweb-0:7.5.32-2.Final_redhat_1.2.ep6.el72022-06-30redhat
redhateap7-log4j-0:2.17.1-1.redhat_00001.1.el7eap2022-04-11redhat
redhateap7-log4j-0:2.17.1-1.redhat_00001.1.el8eap2022-04-11redhat
redhatlog4j2022-04-11redhat
redhattomcat-native-0:1.2.23-26.redhat_26.ep7.el72022-02-14redhat
redhatpatch2022-02-14redhat
redhatsnmp4j-0:3.6.4-0.1.el8ev2022-02-08redhat
redhatrh-sso-7/sso7-rhel8-operator-bundle:7.5.1-92022-02-07redhat
redhatrh-sso7-keycloak-0:15.0.4-1.redhat_00003.1.el8sso2022-02-07redhat
redhatrh-sso7-keycloak-0:15.0.4-1.redhat_00003.1.el7sso2022-02-07redhat
redhatrh-sso-7/sso74-openshift-rhel8:7.4-452022-02-07redhat
redhatrh-sso-7/sso74-openj9-openshift-rhel8:7.4-602022-02-07redhat
redhateap7-log4j-jboss-logmanager-0:1.2.2-1.Final_redhat_00002.1.el7eap2022-02-03redhat
redhatlog4j-jboss-logmanager-0:1.1.4-3.Final_redhat_00002.1.ep6.el72022-02-03redhat
redhatparfait:0.5-8040020220124230039.d304d9ed2022-01-26redhat
redhatparfait:0.5-8010020220124232535.d57017702022-01-26redhat
redhatparfait:0.5-8050020220124063900.6b489b782022-01-26redhat
mavenlog4j:log4j—ghsa
mavenorg.zenframework.z8.dependencies.commons:log4j-1.2.17—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(2 across 1 ecosystem)
Maven(2)
PackageVulnerable rangeFixed inDependents
log4j:log4j1.2.11 ... 1.2.9 (13 versions)——
org.zenframework.z8.dependencies.commons:log4j-1.2.172.0——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(19)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 10× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-26 14:52 UTCEPSS rescore
  2. 2026-07-24 14:15 UTCEPSS rescore
  3. 2026-07-24 14:15 UTCEPSS rescore
  4. 2026-07-23 14:16 UTCEPSS rescore
  5. 2026-07-23 02:04 UTCEG score recompute▲ 1.40
  6. 2026-07-22 22:50 UTCEG score recompute
  7. 2026-07-22 14:06 UTCEPSS rescore
  8. 2026-07-21 15:22 UTCEPSS rescore
  9. 2026-07-21 15:22 UTCEPSS rescore
  10. 2026-07-20 17:05 UTCEPSS rescore
  11. 2026-07-18 05:59 UTCOSV refresh
  12. 2026-07-16 17:00 UTCEPSS rescore
  13. 2026-07-16 17:00 UTCEPSS rescore
  14. 2026-07-15 16:55 UTCEPSS rescore
  15. 2026-07-13 22:27 UTCEPSS rescore
  16. 2026-07-09 19:07 UTCEPSS rescore
  17. 2026-07-09 19:07 UTCEPSS rescore
  18. 2026-07-07 13:43 UTCEPSS rescore
  19. 2026-07-04 06:29 UTCEPSS rescore
  20. 2026-07-04 06:29 UTCEPSS rescore
  21. 2026-07-01 15:04 UTCEPSS rescore
  22. 2026-06-30 23:20 UTCEPSS rescore
  23. 2026-06-30 02:30 UTCOSV refresh
  24. 2026-06-28 14:05 UTCEPSS rescore
  25. 2026-06-27 03:07 UTCEPSS rescore
Show 33 more
  1. 2026-06-27 03:06 UTCEPSS rescore
  2. 2026-06-25 13:48 UTCEPSS rescore
  3. 2026-06-25 13:48 UTCEPSS rescore
  4. 2026-06-23 21:31 UTCEPSS rescore
  5. 2026-06-23 21:31 UTCEPSS rescore
  6. 2026-06-21 01:58 UTCEPSS rescore
  7. 2026-06-21 01:58 UTCEPSS rescore
  8. 2026-06-16 17:51 UTCEPSS rescore
  9. 2026-06-15 17:46 UTCEPSS rescore
  10. 2026-06-14 23:15 UTCEPSS rescore
  11. 2026-06-14 23:15 UTCEPSS rescore
  12. 2026-06-13 22:58 UTCEPSS rescore
  13. 2026-06-13 22:58 UTCEPSS rescore
  14. 2026-06-12 23:10 UTCEPSS rescore
  15. 2026-06-12 15:10 UTCOSV refresh
  16. 2026-06-11 13:58 UTCEPSS rescore
  17. 2026-06-10 22:16 UTCEPSS rescore
  18. 2026-06-08 14:15 UTCEPSS rescore
  19. 2026-06-08 14:15 UTCEPSS rescore
  20. 2026-06-08 14:15 UTCEPSS rescore
  21. 2026-06-07 15:23 UTCEPSS rescore
  22. 2026-06-07 15:23 UTCEPSS rescore
  23. 2026-06-05 06:09 UTCEPSS rescore
  24. 2026-06-05 06:09 UTCEPSS rescore
  25. 2026-06-01 13:50 UTCEPSS rescore
  26. 2026-06-01 13:50 UTCEPSS rescore
  27. 2026-05-31 00:15 UTCEPSS rescore
  28. 2026-05-31 00:15 UTCEPSS rescore
  29. 2026-05-29 13:42 UTCEPSS rescore
  30. 2026-05-26 06:27 UTCEG score recompute
  31. 2026-05-26 06:27 UTCVendor advisory
  32. 2026-05-26 06:27 UTCGHSA enrichment
  33. 2026-05-25 10:46 UTCOSV refresh

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCcckuailong/log4shell_1.x
    First seen Dec 14, 2021

    log4j 1.x RCE Poc -- CVE-2021-4104

    Open source ↗

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2021-4104?
CVE-2021-4104 is a high vulnerability published on December 14, 2021. JMSAppender in Log4j 1.2 is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration. The attacker can provide TopicBindingName and TopicConnectionFactoryBindingName configurations causing JMSAppender to perform JNDI requests that result in…
When was CVE-2021-4104 disclosed?
CVE-2021-4104 was first published in the National Vulnerability Database on December 14, 2021, with the most recent update on May 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-4104 actively exploited?
CVE-2021-4104 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 81% probability of exploitation in the next 30 days, which ranks it in the top 0.4% of all scored CVEs.
What is the CVSS score of CVE-2021-4104?
CVE-2021-4104 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.9.
How do I remediate CVE-2021-4104?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-4104, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-4104

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