Asset Pipeline plugin for Grails vulnerable to Path Traversal

An issue was discovered in the Asset Pipeline plugin before 3.0.4 for Grails. An attacker can perform directory traversal via a crafted request when a servlet-based application is executed in Jetty, because there is a classloader vulnerability that can allow a reverse file traversal route in AssetPipelineFilter.groovy or AssetPipelineFilterCore.groovy.