Known CVE

Apache Solr <=8.3.1 - Remote Code Execution

Apache Solr versions 5.0.0 to 8.3.1 are vulnerable to remote code execution vulnerabilities through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/ directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).