SB2021122020 - Red Hat Enterprise Linux update for log4j 



SB2021122020 - Red Hat Enterprise Linux update for log4j

Published: December 20, 2021 Updated: April 15, 2022

Security Bulletin ID SB2021122020
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Deserialization of Untrusted Data (CVE-ID: CVE-2021-4104)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in JMSAppender, 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.

Note this issue only affects Log4j 1.2 when specifically configured to use JMSAppender, which is not the default.


Remediation

Install update from vendor's website.