CVE-2013-4154
The qemuAgentCommand function in libvirt before 1.1.1, when a guest agent is not configured, allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via vectors related to "agent based cpu (un)plug," as demonstrated by the "virsh vcpucount foobar –guest" command.
Date published : 2013-09-30
http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=96518d4316b711c72205117f8d5c967d5127bbb6