The Solr plugin of Apache OFBiz is configured by default to automatically make a RMI request on localhost, port 1099. In version 18.12.05 and earlier, by hosting a malicious RMI server on localhost, an attacker may exploit this behavior, at server start-up or on a server restart, in order to run arbitrary code. Upgrade to at least 18.12.06 or apply patches at https://issues.apache.org/jira/browse/OFBIZ-12646.