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 (99th percentile of EPSS-scored CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
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 services: Not assessed

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
8.9HIGHhigh confidence
EG Risk
72
EG Risk 72/100CISA SSVC

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%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
81%
EPSS %ILE
99th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

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
redhatMentions a patch (unverified)

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 / EcosystemFix (by version range) / 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

(7 across 6 ecosystems)
Maven(2)
PackageVulnerable rangeFix by version rangeDependents
log4j:log4j1.2.11 ... 1.2.9 (13 versions)
  • 1.2.0 through 1.2.17: no fix on record
—
org.zenframework.z8.dependencies.commons:log4j-1.2.172.0
  • every version through 2.0: no fix on record
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
apache-log4j1.21.2.17-10
  • every version up to 1.2.17-10+deb11u1: fixed in 1.2.17-10+deb11u1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
apache-log4j1.2—
  • every version up to 1.2.17-11: fixed in 1.2.17-11
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
apache-log4j1.2—
  • every version up to 1.2.17-11: fixed in 1.2.17-11
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
apache-log4j1.2—
  • every version up to 1.2.17-11: fixed in 1.2.17-11
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
apache-log4j1.21.2.17-7, 1.2.17-7+deb9u1
  • every version up to 1.2.17-7+deb9u2: fixed in 1.2.17-7+deb9u2
—

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 2× in last 7d / 16× 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. 2026-10-07 23:45 UTCEPSS rescore
  2. 2026-10-06 15:14 UTCEPSS rescore
  3. 2026-10-02 16:23 UTCEPSS rescore
  4. 2026-09-30 15:41 UTCEG score recompute
  5. 2026-09-30 15:00 UTCEPSS rescore
  6. 2026-09-26 15:54 UTCEPSS rescore
  7. 2026-09-25 10:06 UTCOSV refresh
  8. 2026-09-24 14:00 UTCEPSS rescore
  9. 2026-09-24 14:00 UTCEPSS rescore
  10. 2026-09-23 13:45 UTCEPSS rescore
  11. 2026-09-22 14:44 UTCEPSS rescore
  12. 2026-09-21 20:28 UTCEPSS rescore
  13. 2026-09-18 19:24 UTCEPSS rescore
  14. 2026-09-17 19:23 UTCEPSS rescore
  15. 2026-09-16 14:05 UTCEPSS rescore
  16. 2026-09-16 14:05 UTCEPSS rescore
  17. 2026-09-06 13:45 UTCEPSS rescore
  18. 2026-09-06 01:30 UTCOSV refresh
  19. 2026-09-05 15:25 UTCEPSS rescore
  20. 2026-09-04 13:57 UTCEPSS rescore
  21. 2026-09-01 13:51 UTCEPSS rescore
  22. 2026-08-30 19:14 UTCEPSS rescore
  23. 2026-08-30 01:19 UTCEPSS rescore
  24. 2026-08-28 21:38 UTCEPSS rescore
  25. 2026-08-26 14:43 UTCEPSS rescore
Show 69 more
  1. 2026-08-25 13:46 UTCEPSS rescore
  2. 2026-08-24 14:13 UTCEPSS rescore
  3. 2026-08-21 23:46 UTCEPSS rescore
  4. 2026-08-19 17:01 UTCEPSS rescore
  5. 2026-08-19 12:59 UTCOSV refresh
  6. 2026-08-17 13:44 UTCEPSS rescore
  7. 2026-08-16 02:11 UTCEPSS rescore
  8. 2026-08-13 21:57 UTCEPSS rescore
  9. 2026-08-12 13:48 UTCEPSS rescore
  10. 2026-08-04 08:27 UTCOSV refresh
  11. 2026-07-28 15:33 UTCEPSS rescore
  12. 2026-07-26 14:52 UTCEPSS rescore
  13. 2026-07-24 14:15 UTCEPSS rescore
  14. 2026-07-24 14:15 UTCEPSS rescore
  15. 2026-07-23 14:16 UTCEPSS rescore
  16. 2026-07-23 02:04 UTCEG score recompute▲ 1.40
  17. 2026-07-22 22:50 UTCEG score recompute
  18. 2026-07-22 14:06 UTCEPSS rescore
  19. 2026-07-21 15:22 UTCEPSS rescore
  20. 2026-07-21 15:22 UTCEPSS rescore
  21. 2026-07-20 17:05 UTCEPSS rescore
  22. 2026-07-18 05:59 UTCOSV refresh
  23. 2026-07-16 17:00 UTCEPSS rescore
  24. 2026-07-16 17:00 UTCEPSS rescore
  25. 2026-07-15 16:55 UTCEPSS rescore
  26. 2026-07-13 22:27 UTCEPSS rescore
  27. 2026-07-09 19:07 UTCEPSS rescore
  28. 2026-07-09 19:07 UTCEPSS rescore
  29. 2026-07-07 13:43 UTCEPSS rescore
  30. 2026-07-04 06:29 UTCEPSS rescore
  31. 2026-07-04 06:29 UTCEPSS rescore
  32. 2026-07-01 15:04 UTCEPSS rescore
  33. 2026-06-30 23:20 UTCEPSS rescore
  34. 2026-06-30 02:30 UTCOSV refresh
  35. 2026-06-28 14:05 UTCEPSS rescore
  36. 2026-06-27 03:07 UTCEPSS rescore
  37. 2026-06-27 03:06 UTCEPSS rescore
  38. 2026-06-25 13:48 UTCEPSS rescore
  39. 2026-06-25 13:48 UTCEPSS rescore
  40. 2026-06-23 21:31 UTCEPSS rescore
  41. 2026-06-23 21:31 UTCEPSS rescore
  42. 2026-06-21 01:58 UTCEPSS rescore
  43. 2026-06-21 01:58 UTCEPSS rescore
  44. 2026-06-16 17:51 UTCEPSS rescore
  45. 2026-06-15 17:46 UTCEPSS rescore
  46. 2026-06-14 23:15 UTCEPSS rescore
  47. 2026-06-14 23:15 UTCEPSS rescore
  48. 2026-06-13 22:58 UTCEPSS rescore
  49. 2026-06-13 22:58 UTCEPSS rescore
  50. 2026-06-12 23:10 UTCEPSS rescore
  51. 2026-06-12 15:10 UTCOSV refresh
  52. 2026-06-11 13:58 UTCEPSS rescore
  53. 2026-06-10 22:16 UTCEPSS rescore
  54. 2026-06-08 14:15 UTCEPSS rescore
  55. 2026-06-08 14:15 UTCEPSS rescore
  56. 2026-06-08 14:15 UTCEPSS rescore
  57. 2026-06-07 15:23 UTCEPSS rescore
  58. 2026-06-07 15:23 UTCEPSS rescore
  59. 2026-06-05 06:09 UTCEPSS rescore
  60. 2026-06-05 06:09 UTCEPSS rescore
  61. 2026-06-01 13:50 UTCEPSS rescore
  62. 2026-06-01 13:50 UTCEPSS rescore
  63. 2026-05-31 00:15 UTCEPSS rescore
  64. 2026-05-31 00:15 UTCEPSS rescore
  65. 2026-05-29 13:42 UTCEPSS rescore
  66. 2026-05-26 06:27 UTCEG score recompute
  67. 2026-05-26 06:27 UTCVendor advisory
  68. 2026-05-26 06:27 UTCGHSA enrichment
  69. 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 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 (99th percentile of EPSS-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 (HIGH).
How do I remediate CVE-2021-4104?
A fix for CVE-2021-4104 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-4104 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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