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Case File

CVE-2021-4104

HIGH · CVSS 7.5 EPSS 81.15% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-12-14 · Last synced 2026-08-04

CyberRota Analysis

This is a high severity vulnerability with a CVSS score of 7.5. It affects Apache. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 81.1% probability of exploitation in the next 30 days. It may be remotely exploitable.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-4104
Severity
HIGH
CVSS
7.5
EPSS
81.15%
Apache

Original NVD 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.

Related CVEs

Other vulnerabilities affecting the same vendor(s)