CVE-2021-4104

CVSS 7.5 · HIGH
EPSS p99
Higher than 99% of all CVEs — imminent exploitation likely.
No patch reference
No patch/mitigation in references

Published 12/14/2021 · updated 5/28/2026 · CWE-502

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Summary

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 7.5HIGH

7.5 / 10
  • AV: Network
  • AC: High complexity
  • PR: Low privileges
  • UI: No user interaction
  • S: Scope unchanged
  • C: Confidentiality: High
  • I: Integrity: High
  • A: Availability: High

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

EPSS exploitation probability

72.2%

Percentile p99 Higher than 99% of all CVEs — imminent exploitation likely.

Affected products

46 vendor/product entries
  • Apache Log4jv1.2
  • Fedoraproject Fedorav35
  • Redhat Codeready Studiov12.0
  • Redhat Integration Camel Kall versions
  • Redhat Integration Camel Quarkusall versions
  • Redhat Jboss A Mqv6.0.0, v7
Do you run any of these? Sign in to match this CVE against your SBOM and asset inventory automatically.

Timeline

  1. Dec 14, 2021 · Disclosed / published in NVD
  2. May 28, 2026 · Intel last updated

Intel sources

Which upstream feeds returned data for this CVE, and when they were last fetched.

  • NVD· 60 days ago
  • CVE.org· no data
  • FIRST EPSS· 60 days ago
  • CISA KEV· no data
  • OSV· no data

References

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