CVE-2020-9493 identified a deserialization issue that was present in Apache Chainsaw. Prior to Chainsaw V2.0 Chainsaw was a component of Apache Log4j 1.2.x where the same issue exists.
https://lists.apache.org/thread/rg4yyc89vs3dw6kpy3r92xop9loywyhh
https://logging.apache.org/log4j/1.2/index.html