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CVE-2021-4104

Deserialization of untrusted data in JMSAppender in Apache Log4j 1.2

Published: Dec 14, 2021Updated: May 28, 2026 Sources: CVE List NVD GHSA BDUCWE-502
NVD MITRE
7.5CVSSHIGH
EPSS Score
81.1%
Top 0.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

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 Vector Breakdown

AV:NAC:HPR:LUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-502

Affected Products

Apache Log4j 1.xApache Software Foundation
Mixed
Web & CMS Plugins / cms-core
log4j:log4jMavenOSS Libraries
org.zenframework.z8.dependencies.commons:log4j-1.2.17MavenOSS Libraries
Red Hat Enterprise LinuxRed Hat Inc.
On-premOS
Operating Systems / linux-distro
Jboss FuseRed Hat Inc.
On-premWeb App
DevTools & CI / build-test-tools
apache software foundationoss-projectUSWeb & CMS Pluginsaka apache foundation
mavenpackage-ecosystemOSS Libraries
red hat inc.commercialUSOperating Systemsaka red hat
and 66 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

3 techniques
Execution
Initial Access
View detailed technique mapping

References

https://www.cve.org/CVERecord?id=CVE-2021-44228
cve.org
https://github.com/apache/logging-log4j2/pull/608#issuecomment-990494126
github.com
https://access.redhat.com/security/cve/CVE-2021-4104
access.redhat.com
and 20 more references View all →

Timeline

Published
Dec 14, 2021
Last Updated
May 28, 2026

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