CVE-2021-4104 - Remote Code Execution (RCE)
Severity: Low2021-12-29
Abstract
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.
The Oxygen XML products incorporate the Apache Log4j2 as a third-party library. This advisory was opened to address the potential impact of this third-party library vulnerability.
Affected Products/Versions
| Product | Severity | Fixed Release Availability |
| Oxygen Content Fusion v2.0.3 | Low | Oxygen Content Fusion 2.0.4 build 2021122211 |
Mitigation
Make sure that JMS Appender is not configured in your Log4j configuration. You can do this by inspecting the Log4j configuration file. If you find a line containing the org.apache.log4j.net.JMSAppender, you may be vulnerable.
Detail
CVE-2021-4104
Severity: High
CVSS Score: 8.1
The Apache Log4j third-party library used by Oxygen XML products is an affected version mentioned in CVE-2021-4104 vulnerability description. However, our default configuration does not use JSM Appender and the vulnerability can be only exploited by modifying the logging configuration by a trusted party. For that reason, we have rated the severity level for our products as low.
