The DataImportHandler, an optional but popular module to pull in data from databases and other sources, has a feature in which the whole DIH configuration can come from a request's "dataConfig" parameter. The debug mode of the DIH admin screen uses this to allow convenient debugging / development of a DIH config. Since a DIH config can contain scripts, this parameter is a security risk. Starting with version 8.2.0 of Solr, use of this parameter requires setting the Java System property "enable.dih.dataConfigParam" to true.
- Upgrade to 8.2.0 or later, which is secure by default.
- or, edit solrconfig.xml to configure all DataImportHandler usages with an "invariants" section listing the "dataConfig" parameter set to am empty string.
- Ensure your network settings are configured so that only trusted traffic communicates with Solr, especially to the DIH request handler. This is a best practice to all of Solr.
- Michael Stepankin