Red Hat Security Advisory 2015-2290-01 – The pcs package provides a configuration tool for Corosync and Pacemaker. It permits users to easily view, modify and create Pacemaker based clusters. The pcs package includes Rack, which provides a minimal interface between webservers that support Ruby and Ruby frameworks. A flaw was found in a way Rack processed parameters of incoming requests. An attacker could use this flaw to send a crafted request that would cause an application using Rack to crash.