The Simple Protocol for Independent Computing Environments is a remote display protocol used in Red Hat Enterprise Linux for viewing virtualized guests running on the Kernel-based Virtual Machine hypervisor, or on Red Hat Enterprise Virtualization Hypervisor. The qspice-client package provides the client side of the SPICE protocol. A race condition was found in the way the SPICE Mozilla Firefox plug-in and the SPICE client communicated. A local attacker could use this flaw to trick the plug-in and the SPICE client into communicating over an attacker-controlled socket, possibly gaining access to authentication details, or resulting in a man-in-the-middle attack on the SPICE connection. Users of qspice-client should upgrade to this updated package, which contains a backported patch to correct this issue.