CVE-2021-44228 – Log4j 2 Vulnerability Analysis

A high severity vulnerability (CVE-2021-44228) impacting multiple versions of the Apache Log4j 2 utility was disclosed publicly via the project’s GitHub on December 9, 2021. This vulnerability, which was discovered by Chen Zhaojun of Alibaba Cloud Security Team, impacts Apache Log4j 2 versions 2.0 to 2.14.1. There are reports from Log4j maintainers that the 1.x series may also vulnerable to this issue when using the JMS Appender class.

The vulnerability allows for unauthenticated remote code execution. Log4j 2 is an open source Java logging library developed by the Apache Foundation. Log4j 2 is widely used in many applications and is present, as a dependency, in many services. These include enterprise applications as well as numerous cloud services.