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 spice-xpi package provides a plug-in that allows the SPICE client to run from within Mozilla Firefox. A race condition was found in the way the SPICE 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. It was found that the SPICE Firefox plug-in used a predictable name for its log file. A local attacker could use this flaw to conduct a symbolic link attack, allowing them to overwrite arbitrary files accessible to the user running Firefox. This update also fixes the following bugs: * a bug prevented users of Red Hat Enterprise Linux 5.5, with all updates applied, from running the SPICE Firefox plug-in when using Firefox 3.6.4. With this update, the plug-in works correctly with Firefox 3.6.4 and the latest version in Red Hat Enterprise Linux 5.5, Firefox 3.6.7. * unused code has been removed during source code refactoring. This also resolves a bug in the SPICE Firefox plug-in that caused it to close random file descriptors. Note: This update should be installed together with the RHSA-2010:0632 qspice-client update: https://rhn.redhat.com/errata/RHSA-2010-0632.html Users of spice-xpi should upgrade to this updated package, which contains backported patches to correct these issues. After installing the update, Firefox must be restarted for the changes to take effect.