Apache Flume versions 1.4.0 through 1.10.1 are vulnerable to a remote code execution (RCE) attack when a configuration uses a JMS Source with an unsafe providerURL. This issue is fixed by limiting JNDI to allow only the use of the java protocol or no protocol.
https://lists.apache.org/thread/939wkx8o90bp6m2ht3t1sdyo1ncypl78
https://lists.apache.org/thread/1ckhmp539zr2nd2rs45pocpywk2d9zvz