Race condition in the VMware driver in OpenStack Compute (Nova) before 2014.1.4 and 2014.2 before 2014.2rc1 allows remote authenticated users to access unintended consoles by spawning an instance that triggers the same VNC port to be allocated to two different instances.
https://bugs.launchpad.net/nova/+bug/1357372
http://www.securityfocus.com/bid/70182
http://www.openwall.com/lists/oss-security/2014/10/14/9
http://secunia.com/advisories/60227
http://rhn.redhat.com/errata/RHSA-2014-1782.html
http://rhn.redhat.com/errata/RHSA-2014-1781.html
http://rhn.redhat.com/errata/RHSA-2014-1689.html
http://lists.openstack.org/pipermail/openstack-announce/2014-October/000293.html