GeoNetwork is a catalog application to manage spatially referenced resources. Prior to versions 4.4.12 and 4.2.17, the Saxon XSLT processor

GeoNetwork is a catalog application to manage spatially referenced resources. Prior to versions 4.4.12 and 4.2.17, the Saxon XSLT processor used to render formatters is configured without secure processing (FEATURE_SECURE_PROCESSING) and without disabling Java extension functions (ALLOW_EXTERNAL_FUNCTIONS). Any stylesheet loaded by GeoNetwork can therefore invoke
java.lang.Runtime.exec() or java.lang.ProcessBuilder directly, achieving arbitrary command execution as the GeoNetwork process user. A user with sufficient privileges to upload a formatter can deliver a .xsl file containing Java extension call that execute arbitrary OS commands with the privileges of the GeoNetwork process. The issue is patched in GeoNetwork versions 4.4.12 and 4.2.17.