VULNERABILITY INTELLIGENCE
CVE-2021-4104
CVSS score7.5 HIGH
EPSS probability80.60%
CISA KEVNot currently listed
Published2021-12-14
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
Weakness classification
- security@apache.org: CWE-502
- nvd@nist.gov: CWE-502